So I bought a c200 coupe few months ago at 48000km and it clearly has been having some issues with the suspension/handling since the day one I owned the car. The symptoms are: Nervousness and unpredictable loose feeling in high speed passing situations (seriously difficult to drive on a road that has deep grooves), and also pulling slowly to one or another side when accelerating quickly. So if I floor it I usually have to slightly counter steer to keep my direction, and when I release the throttle it just turns to the opposite direction quickly, so I have to correct again. This is very annoying and not how a RWD should handle in my opinion. Also the car feels quite bouncy sideways (like wiggling when cornering slowly), and also keeps wiggling back and forward when I brake to stop as can be seen in the video in the link. To me this definitely looks like an issue with the shocks (all the 4, not just some of them), but all the tests say they are fine (I know the tests are mostly bs though):
https://www.dropbox.com/scl/fi/cx6qt...4969uca3l&dl=0

The shop (official Mercedes dealer) found an actual issue though which has been fixed now. The steering rack "thrust piece" or "yoke" was loosened up allowing the steering rack to have some play (yes, at 48000km....). This resulted in knocking sound when slowly turning and going over bumps or edges. I was really hoping that the issues were gone after they installed the repair kit and re-aligned everything, but the issues are still there and the only thing that disappeared is the knocking noise. Yeah the steering might feel slightly stiffer now, but that's it. Still the car is not handling as a 205 mercedes should (I've owned or test driven many different W or S205's and never experienced anything like this). I brought the car to the dealer again and they checked all the related bushings, control arms etc. (as they say) but couldn't find anything loose or broken. Also the power steering software was updated, but the loose feeling and bad handling is still there...

Just to mention, the car has the basic Avantgarde suspension from the factory (same as standard suspension but 15mm lower), but to me it feels like they clearly put some kind of stiffer springs there to add some sportiness to the coupe version maybe. Because compared to a S205 wagon with the same Avantgarde basic suspension, the coupe feels a lot stiffer and less body roll. So there is a slight possibility that the standard shocks can't really hold up with the stiffer springs, resulting in handling issues as described. The suspension is stock however, no after market springs or anything.

But what do you think? I'm currently trying to find another coupe with the same Avantgarde suspension to test drive and see if it handles like this or not. Most of the coupes here have been specced with the 486 sport suspension so it's difficult to find one for a comparison.

Tires might be a reason for something, but I don't really think they could affect that much. I've been driving many 205's with the same AMG 18" wheels and similar tires and never encountered such issues.