In Parts: Facelift Taillights, we discussed the taillights manufactured by ULO over the past 30 years. In short, those taillights can now only be ordered through MB aftersales, and they come at a high cost—while quite possibly bringing even more trouble. So, is there any alternative that could turn things around?
10 years ago, when we still offered public repair services, taillight replacement on the W140 was almost a mandatory item. Any car in need of serious repair would naturally struggle to preserve its original taillights intact, as they were among the most fragile exterior components. What we found, however, was that for roughly 90% of owners, even after being able to afford a one-time repair bill exceeding $20,000, they still preferred to compromise by installing DEPO taillights—or simply doing nothing—instead of using genuine ULO-made parts. This was despite the fact that back then, ULO taillights were far more available and considerably less expensive than they are today.
Beyond the price, the biggest reason people gave up on genuine ULO parts was the unavoidable color mismatch. Because of this, we always warned customers about the potential consequences of replacing single taillight, and consistently recommended replacing all three pieces as a complete set. During sourcing, we carefully screened the colors to make sure the customer would not lose their mind over the result. Still, many people simply could not accept replacing an entire taillight set just because one of the three pieces needed replacement—perhaps only due to a localized water leak—in order to maintain color consistency. That is completely understandable.
As we have mentioned before, since entering production in 1994, ULO taillights have come with at least three different factory tint variations in the transparent sections, making parts from different periods difficult to match properly. For example, the center reflector is usually more fragile in service, as its thin middle connection area is prone to cracking from the movement of the trunk lock mechanism. At the same time, because the center reflector is less likely to be scratched or damaged in an accident, far fewer replacement units were produced compared to the left and right taillights. As a result, finding a center reflector that matches the color of both sides adds another layer of difficulty.
Once people were clearly warned about these visual issues, many changed their minds entirely. As a disclaimer, we also classified water leakage as a 100% factory defect and therefore insisted on resealing every ULO taillight before installation. After hearing warning after warning, many began to feel that the value proposition of ULO products was becoming increasingly poor. Some, following the “the best or nothing” philosophy, simply chose not to replace them at all. Of course, others tried to source used taillights with similar fading, but a set of pinkish, sun-faded transparent plastic hardly improves the appearance of the car.
Another compromise was DEPO—the subject of today’s discussion. Originally, this should not even have been worth discussing. But DEPO costs only about one-third of a flawed ULO unit, and more importantly, its product quality slightly exceeds that discount. On the surface, both DEPO and ULO suffer from color mismatch and water leakage, so some people simply choose to spend less money on flawed parts. The interesting part is that although DEPO taillights have issues far beyond those two problems found in ULO units, there are also areas where DEPO actually outperforms ULO.
Taiwanese manufacturer DEPO began producing facelift taillights for the W140 from the very beginnin, it appeared in their 1997 catalog. Although DEPO manufactured a large number of lighting products for Mercedes, they never had an official partnership with MB, and in recent years they have been involved in litigation due to patent disputes. DEPO’s arrival challenged ULO’s dominance in the market. During the period when W140 values hit rock bottom, spending one-fifth of the car’s value on a full set of ULO taillights was simply unrealistic. The more economical DEPO naturally gained the upper hand in sales. Even in Europe, where trust in European-made products remains strong, we believe DEPO likely surpassed ULO in sales many years ago.
The first W140 taillight model produced by DEPO was 440-1913-UE-YR, a facelift version featuring amber turn signal lenses. They never produced a pre-facelift version. This may be because in East Asia, S-Class owners often vanity-upgrade their cars’ appearance to match newer factory styling, leaving little demand for the older taillight design. This taillight is not really within the scope of today’s discussion, as it has been discontinued for a long time and is now virtually impossible to find in stock. And yes, this is also an older-style product—many owners tend to install the later taillights with clear turn signal lenses to make their cars look newer.
The second product is 440-2901, the center reflector panel. It fits both facelift taillight versions—those with amber and clear turn signals. Because DEPO pricing was highly affordable—roughly one-tenth of what an MB dealer would charge for this particular part—buyers often chose to replace the entire DEPO taillight set to eliminate color mismatch altogether. After all, DEPO parts were never going to match aged factory parts anyway. As a result, DEPO produced a large number of these center reflector panels, so supply has never been an issue. Finding the equivalent part from ULO, on the other hand, is much more difficult.
The third product, 440-1913-UE-CR, is today’s main subject—the facelift taillight with clear turn signal lenses. This product was manufactured in large quantities and remains in production today. The product image is slightly misleading, however, as DEPO neither manufactures nor supplies the bulb carrier; that should be an original factory component. Well, these catalog images alone may already be enough to scare off some connoisseurs. The layout of this wholesale catalog carries an almost amateurish quality—something that feels distinctly non-industrial-civilization in nature. Accordingly, one might expect the product quality to be equally uninspiring.
Let’s take a look.
Originally, we never considered alternatives outside ULO. DEPO, despite being more popular than ULO, never made it onto our supplier list. Our unpleasant experiences with DEPO included rough manufacturing quality, inaccurate colors, and, admittedly, a certain prejudice toward its country of origin. It has been over ten years since we last touched a DEPO product. Back then, they had sharp edges that did not align properly with the body, transparent housings with an ugly purple tint, and of course, water leakage. Sometimes even the three pieces within the same set had different shades because they came from different production batches.
This was the first car we restored —a 1997 S 320. At the owner’s request, it was painted in two-tone that was not period-correct for the car. You can clearly see the color difference between the right taillight and the center reflector’s transparent plastic. The camera has softened this difference; in person, it was far more obvious. I remember this vividly: during the six-month restoration, we simply could not find a set of ULO taillights with consistent coloration. Meanwhile, the DEPO center reflector was noticeably darker than the left and right. Faced with the same level of trouble either way, the owner chose to waste less money on the compromise. Still, in the photos, it doesn’t look too bad, does it?
A turning point came in 2025, when I removed a pair of taillights from a donor car. The left and right sides had fairly similar coloration. The right side had already lost a large portion of its chrome coating due to water intrusion; without question, it was a ULO unit manufactured in 2010. The left side, which I initially assumed was also ULO, turned out to be DEPO—to my surprise. I held it in my hands for quite a while, comparing it against genuine parts, unable to let go of the thought. This DEPO achieved at least half the quality of a genuine part. It was nowhere near as bad as I remembered. Was my memory failing me?
I immediately contacted a trusted parts dealer to confirm a full three-piece set with no visible color mismatch and placed the order. Normally, we would never waste time or money on something like this, but it seemed like an interesting study. Next, we will compare DEPO with ULO models from different periods. We will use the factory-installed genuine taillights as a standard and break them down into a total of 10 points for evaluation.
Our reference standard is a NOS taillight produced in 12/96. It was manufactured shortly after the launch of MY1997, making it a relatively early production unit. Because it was produced during the same period as the parts originally installed on the cars, it should possess the same material quality and overall character. Based on all of our past experience, we have also repeatedly confirmed that this taillight is fully qualified to serve as the benchmark.
1. First glance：3/4
The real-world use case of exterior parts is “the first glance”. If a reproduction part looks right at first glance, we may be willing to tolerate flaws discovered later—and then discuss what it cost. But if it looks awkward from the very first moment, no matter how hard we try to convince ourselves otherwise, that psychological barrier will always remain. Do not waste time on such parts.That is why, in our 10-point evaluation system for taillights, first galance alone accounts for half of the total weight.
Let us begin with a test. Above is a close-up of the taillights on a 1997 S 600 after restoration. Do you think these new taillights look acceptable? Or, if this car appeared on Bring a Trailer, would you be confident enough to identify them as non-factory parts? Would you be confident enough to step forward, warn the bidders, and potentially knock down the final hammer price?
Since I have already said this much, of course—they are DEPO. But we should not approach the question with a predetermined conclusion.Although this car was delivered to a friend by us more than ten years ago, and I clearly remember the disappointment of holding those taillights in my hands, when I look at these photos again today, I find that I have partly forgotten their flaws. It actually takes me a moment—relying on memory and even old invoices—to confirm that these were not ULO products.
First, when placed side by side (left, DEPO 2025. Right, genuine 1996), the two do indeed look very close at first glance. Nothing particularly special. Even when measured with a ruler rather than judged by the naked eye alone, the dimensions of each colored section on the DEPO unit match those of the ULO exactly. At first glance, the lens shows no obvious fatal flaws. After all, the real-world use case for these parts is precisely “the first glance”—very few people will inspect a taillight up close. By that standard, it is acceptable.
For ULO products, the primary weakness lies in the transparent material itself: it contains compounds that tend to turn red under prolonged sun exposure. This is the root cause of the notorious color mismatch. Even today, if you install a NOS unit from the 1990s, it will quickly develop a reddish or pinkish tint under sunlight. To address this issue, ULO changed the material in the early 2000s, effectively solving the red-shift problem. But this created a new problem: the base color of the material itself changed. The newer material appears noticeably more blue or green, and this shift is easily visible to the naked eye. In other words, the original factory-correct tint has effectively become extinct—even if that exact shade only existed briefly in the first place.
The tint of DEPO’s transparent material carries a more noticeable purple hue. hey seem, perhaps surprisingly, to have stayed faithful to the factory fade tint when producing their replicas—though this may well be pure coincidence. I have genuinely encountered customers who specifically asked for “pink taillights,” because they believed that was the taillight’s original color. So for owners who insist on having “pink” taillights but cannot source a complete NOS set, choosing DEPO suddenly gains a bit more legitimacy.
However, last year I came across a beautifully restored W140. It was obvious that whoever worked on the car had done their job conscientiously—the result was far above average. But a sharp pair of eyes had already delivered judgment in the comments, : “Such a shame, the taillights aren’t genuine.” That comment was admittedly a bit harsh, but that is exactly how DEPO works. It is only slightly off. Although, in the eyes of a true connoisseur, if it is not the best, it is nothing.
Overall, DEPO earns 4 /5 for first glance. Unless a genuine taillight and a DEPO counterpart are placed side by side, it would be difficult for a non-professioanl to tell them apart from a reasonable distance.
2. Close inspection：1/2
Depending on the distance between the car and the viewer’s eyes, opportunities for close inspection are relatively rare unless we actually own the car. At gatherings such as Cars and Coffee or annual club meetings—places where one may politely admire details of people’s cars —we still do not spend much time examining any single component. No one is going to stare at your taillights for long. For that reason, we assign this category a weight of 2 points, only.
If one deliberately goes looking for differences, DEPO will not waste our time. From the side, the red section on the DEPO unit lacks one reflective area—on both left and right taillights. This difference may well be intentional, perhaps a subtle alteration made by DEPO to avoid patent disputes. Otherwise, there seems to be no reasonable explanation. This reflective area is meant to alert approaching traffic from the side at night when the car is parked. Is its absence fatal? Probably not. But it would almost certainly make the taillight non-compliant in certain markets.
As we have repeatedly pointed out, the continuous changes accumulated throughout ULO’s long production history mean that even ULO can no longer faithfully reproduce the original factory parts. As a result, there may actually be certain characteristics that DEPO still preserves today, while ULO itself has failed to carry them forward. The situation is somewhat reminiscent of Ancient Greek philosophy. Much of it was nearly lost during the Middle Ages, but fortunately survived through Arabic translations preserved in Baghdad, only to be translated once again and reintroduced to Europe during the Renaissance.
Another factor that is crucial to close-range visual impression is the chrome finish of the reflector. For this topic, it makes more sense to compare DEPO against the latest parts we can still order through MB aftersales, because even those parts can no longer achieve a perfect score. For example, due to changes in the manufacturing process, the chrome on newer ULO units is excessively bright. This gives the part a somewhat cheap—or at least overly exaggerated—appearance. Compared with a ULO taillight produced in 2016, the chrome finish on the DEPO reflector appears more restrained and more natural.
DEPO certainly cannot withstand prolonged scrutiny. In fact, with the help of its signature differences, it can be identified from several meters away. So even though its chrome finish performs surprisingly well, it can only receive half of the available points.
3. Manufacturing quality：1/2
If one insists on appreciating a taillight as a standalone object, manufacturing quality becomes another dimension in which the gap between ideal and reality widens even further beyond the design itself. Production is such a vast discipline. Even if each individual component is molded reasonably well, assembly precision becomes an entirely separate challenge. We assign this category a weight of 2, because in practical use, it is not particularly critical.
Under ideal conditions, DEPO should have carefully studied the genuine taillights and produced a 100% faithful copy. Today, this may not be particularly difficult. In terms of manufacturing complexity, these taillights are not fundamentally different from those found on a modern Chinese car costing around $6,000. They are housings with alternating red and clear lenses welded onto a chrome-plated base. There is no longer any real technical barrier to producing this type of product. However, DEPO’s reproduction technology is at least from 1997.
The stamp indicates that DEPO started producing this mold in 2002, but it has been listed in DEPO’s catalog since at least 1997. Of course, the production date box on the DEPO unit had long since been filled in, so we have no way of knowing its exact manufacturing year. It is worth pointing out that, if you remember the 2016 ULO taillight from our earlier review, its rear housing was covered with the unsightly crackle pattern that has become characteristic of recent production. As shown below. (Upper, ULO 2016. Lower, DEPO 2025)
First, there are the excessively sharp mold lines formed where the two halves of the mold meet—a common issue in inexpensive plastic products. Even high-quality products are not entirely free from such seams, but they usually include a finishing stage where these edges are sanded and refined. If the installer’s hands are as delicate as a baby’s skin, be careful—it is best to sand and polish these edges beforehand. Fortunately, most of these sharp seams are located on the installation side rather than the visible exterior.
Hey, compared with the ULO 2016 (right), the DEPO 2025 (left) at least doesn’t have chrome runs that look like dried snot, so it wins a point back. If the latest ULO deserves only 1 point for manufacturing quality, then the DEPO—which has its own strengths and weaknesses—deserves the same score.
As for how well a DEPO taillight holds up over time, take a look at this removed used unit (right). It clearly wasn’t in service for very long, so it serves as a reasonable example of a well-preserved car that spent most of its life indoors. The tint of the clear plastic has changed only subtly—if anything, it has become slightly closer to that of the genuine part. The chrome finish, however, shows visible loss of luster. That is something worth paying attention to.
4. Installation fitment：1/2
Practice is the ultimate test of truth. A taillight is not an isolated component; its true quality can only be judged once installed on the car. Publishing this article at the final assembly stage of Big Apple—our 1997 S 420—serves one specific purpose: to properly evaluate the real-world differences between DEPO and ULO after installation. We will first install the ULO set and treat it as the reference standard. Then we will test the DEPO set under the same conditions.
From left to right, the three pieces in this ULO taillight set were produced in 2007, 2015, and 2010 respectively. The 2015 center band is new—or, if we want to be technically precise and avoid calling it truly new, then it qualifies as NOS. The left and right taillights are used ULO parts that were removed after only a short period of service. I wet-sanded them with 3M Trizact 3000 and polished them afterward, bringing the level of surface scratches and gloss effectively in line with brand-new parts. The seals are original factory pieces. They have already been properly compressed over time, which makes installation noticeably easier.
Installation of ULO went smoothly from start to finish, with no difficulties encountered. The gaps between both taillights and the body were even and consistent, with no protrusions or recessed areas.
As expected, installing the DEPO set came with some difficulties—exactly the kind I still remember from more than ten years ago. Meanwhile the color difference is obvious even through the camera.
For ULO, the junctions between the left and right taillights and the center band looks natural and well aligned. Note that the two pieces shown in the photo exhibit a slight color mismatch—a typical ULO issue. Such difference is caused not only by the shade of the transparent plastic, but also by variations in the brightness of the chrome finish.
The matching between the two DEPO pieces is also fine, but the color mismatch is noticeably more pronounced. The center band is clearly manufactured to a lower standard. Its chrome plating is thicker, with visible runs and uneven application. As your viewing angle changes, the reflections across the center band become noticeably inconsistent.
Because the mounting screw holes allow almost no adjustment, the position of the taillights is essentially fixed during installation. This means the final fitment places very high demands on the precision of the parts themselves. Although ULO suffers from inherent issues such as water leakage, color mismatch, and the newer problem of declining production quality, its fit and assembly precision remain as good as ever.
For DEPO, to begin with, every mounting screw actually lined up with its corresponding hole. For a budget aftermarket part, that alone already counts as a victory. However, once installed, the taillights showed a noticeable step relative to the body surface. At close range, the mismatch is obvious. Below is a close-up comparison of the edge details between DEPO (left) and ULO (right).
Before painting Big Apple, we originally considered modifying the taillight recesses to better accommodate the DEPO units. But the dimensional deviation from factory specifications was simply too large. The problem was this: if we later managed to source a proper set of ULO taillights after the paintwork was completed, there would be no easy way to reinstall them correctly without damaging the paint. For that reason, we decided not to alter the fenders. Sometimes you really have to wonder why these aftermarket manufacturers fail at things that seem so fundamentally basic. Is it because if they made parts as good as MB while charging only half the price, MB would never let them get away with it?
Of course, very few people are going to stare at your taillights that closely. This issue is not entirely without a remedy. Some adjustment can be made on the body side—essentially widening the taillight housing area laterally to give the outer edge of the taillight a bit more room. But doing so would compromise the original shape of the fender.
The DEPO units were installed using original factory seals, and even that offered little improvement. If you are going to install DEPO taillights, do not use the seals supplied by DEPO—the material is quite possibly the worst on the market. If possible, sand and polish the edges as well, because there is a real chance they can scratch your hands. Of course, none of these issues are easy to see in photos.
A subtler difference becomes apparent after the bulb carrier is installed. Because the DEPO reflector is less reflective, the amber color from the turn signal bulb is not distributed across the entire reflector as effectively as it is in the ULO unit.
Based on the two images above, we believe the DEPO units deserve 1 out of 2 points in this aspect. They accomplish the fundamentals. At the very least, they allow the car to look convincing in a few good photographs. But for connoisseurs with an uncompromising obsession with originality—or a prejudice against where parts are made—these components may feel as though they have contaminated the car.
Overall, DEPO receives a total score of 6/10, placing it almost exactly on the passing line. Of course, we have not yet discussed cost or durability. When properly cared for, these later-generation ULO taillights will likely retain their appearance almost indefinitely. As for DEPO, that remains an open question. By the way, the DEPO set we purchased cost just 1/10 of the quote for a set of genuine taillights. If, to your eyes, DEPO looks just as good—or just as bad—as ULO, then you can make your choice without hesitation.
Some thoughts
According to MB parts veteran, current situation is as follows: for discontinued older models such as the W140, once the tooling used to produce replacement parts becomes too worn to continue operating, MB becomes cautious about resuming production. The first question is demand. Production will only be reconsidered if there is sufficient market demand to justify it. The second issue is cost. Since the tooling belongs to the manufacturer, developing new tooling would inevitably drive costs up significantly. Previous procurement costs were based on tooling that had already been amortized over 30 years of production. The question then becomes: does it make sense to invest in new tooling to produce quantities that are clearly far lower than what was sold over the previous three decades?
Finally, even if customers are willing to pay a premium, there remains the issue of quality. ULO taillights are a textbook example. Newly manufactured units are, in practice, no longer able to meet the standards of the past. If quality degradation can already be tolerated while continuing production with old tooling simply to maintain supply, there is still no guarantee that products made with entirely new tooling would be as good as they once were. Quality complaints may ultimately erode demand, and once demand collapses, the investment becomes impossible to recover. In the end, we may never see W140 taillights enter production again—or, if they do, they may return only as low-quality units priced at $1,200 apiece.
From a moral standpoint, we are supporters of old-era MB, and today’s Mercedes-Benz is the direct descendant of what we choose to support. Naturally, purchasing non-authorized products means, in some sense, undermining the very entity we stand behind. In the long run, allowing aftermarket products to grow unchecked may further weaken the supply of other genuine parts as well. At present, DEPO offers a convenient way to make a car shine again quickly. But that shine comes at a discount—and with no promises attached. What lies before us is a genuine dilemma.
Those familiar with DEPO may also remember that their products once suffered from color mismatch as well. Today, that issue appears to have largely been eliminated. For us poor W140 owners, being able to have even one of our reasonable taillight expectations fulfilled already feels like a blessing. That is how difficult it is to find a taillight set with consistent coloration. A year ago, we purchased two complete DEPO sets as backups. I carefully resealed one of them the same way we would with a ULO unit, and fitted it with original factory bulb carriers, preparing to install it on Big Apple. Fortunately, at the very last moment, we managed to assemble a three-piece set with almost no visible color mismatch. We currently have more than thirty unfaded taillights in inventory, yet their colors never quite match.
Just like ULO, there is no guarantee that DEPO will continue producing W140 taillights in the future—or that the next production batch will remain free of color mismatch.For that reason, keeping a few recently produced DEPO units as spares is a perfectly reasonable decision. What a pity—DEPO, as an independent manufacturer with no official relationship to MB, should in theory be capable of producing parts comparable to ULO’s at a more sensible price. If that were the case, owners would have little reason to hesitate simply because the parts are made in Taiwan; after all, MB already sources many components from Taiwan. Perhaps one day MB and DEPO should make peace and shake hands, combining DEPO’s cost advantage with proper manufacturing standards to produce taillights as excellent as those from the old days.
Please note that all parts are brand new and purchased in recent times (2025 and 2026), they represent the current status of these manufacturers only and do not imply anything about the past or distant future.