The rust issues on the W202 seem to be the same as on the W210 E-Class. I've seen a few of them loose the front spring perches.
Yup - the E-Class is affected as well.
Mercedes made among the best cars in the world through the 1980s. The first JD Power and other statistical reliability and quality measures ranked MB far ahead of anyone else. But, something changed in 1990. A nuclear bomb was dropped on the luxury car industry. And it was launched by Toyota.
The Lexus LS400 changed the landscape dramatically. It was priced far below the Germans. Targeting Mercedes more than the others - the Lexus looked a lot like MB models (plastic lower cladding, upright grille, etc, etc) and in terms of driving dynamics, placed the V-8 E-Class and SWB S-Class squarely in it's sights.
The kicker? It was priced well below the Mercedes models. At first, the auto industry seemed skeptical that anyone could do what Toyota was doing. But, in short order, they showed that the Lexus not only matched, but in many ways, exceed the Mercedes models in terms of build quality. And at that much lower price.
As the 90's wore on, Mercedes reworked models and pricing, making their cars more attractive compared to the Lexus models. They added electronics and dropped prices. They tried to trim production costs. Corner cutting? Some think so.
One huge stumble was the change to "green" processes. Toyota switched to water-based paints and reworked their rust-proofing and for the most part, it was successful. Mercedes struggled here. The first years of water-based painted cars were terrible. Their change to environmentally friendly rust proofing was a flop - the bodies weren't too bad, but the things like spring perches were not great. When I sold my 1998 C230, it had far more corrosion issues than the 1990 190E I sold not long before that. In fact, the 1990 car had NO rust despite 509,000km and a lot of hard winters.
So today, it not uncommon to see late 90's Mercedes that look
old. Paints faded or chipped easily and the rust resistance of previous models was lacking.
Other things happened in the 90s. The MB Tex of years past was expensive. Not much cheaper to make than leather, actually. Customers loved it because it looked great forever. It was a hallmark of MB interiors, even sold on expensive S-Class cars. During the 90s, they thinned the material to save money. And interiors wore early. The cars lost a lot of their appeal in some ways.
Toyota used their engineering prowess to build electronics that worked. And kept working. The Germans were never all that great with moving electrons around cars. Bosch, VDO and others had been building crap components for Mercedes for decades, and hell, why change now? Even those amazing cars from the 80s had crappy radios, breaking power antennas, barely working cruise control units, and so on. But, people shrugged their shoulders and said "gadgets are for Caddy drivers, I have a Mercedes that is a mechanical wonder." And they were right, pretty much. But Toyota proved that the market wanted a car that was mechanically perfect AND had reliable electronics.
Mercedes began to rush things to market and experimented on customers. Okay, Germans had been doing this forever, but it got worse post-Lexus-introduction. The 722.6 five speed automatic is a perfect example. Mercedes wanted to scoop the other makes by offering a five speed across the entire line. It would be a fully electronically controlled unit, and "filled for life."
What a fiasco. They pretty much all failed. It was never really tested and hardly any of them made it past the warranty period, luckily for buyers. Filled for life also proved to be erroneous - people soon realized it meant "for the life of the warranty." Not changing the fluid every 100K-kms or so meant your trans would be dead. The hilarious thing was even though they insisted it was "fill for life" there was a highly detailed system including software and hardware for changing the fluid. Cripes.
Other things caused people to rethink MB as a brand. They needed to get rid of inline engines and go to V-6s for packaging. Again, they rushed things. Several years of V-6 engines were sold with faulty harmonic balancers that would fly apart, potentially ripping your engine bay to bits.
The list of things like this got long. MB's brand image faltered. The internet didn't help - word spread. We talk about FGCs, right? The term is rooted in fact. BMW and Audi have stories not unlike Mercedes' - quality issues when faced with intense Japanese and other German competition.