Did you just buy the car . . . ?!
As for the suspension, it doesn’t have air suspension. it has ABC active body control, which is nice when it’s working and extremely expensive to repair
afaik, there’s no repair short of replacing the fuel tank . . . this was actually a fairly common repair, and also a very expensive repair. It’s a pita to replace the tank, so expect to be charged accordingly
Booth cover does not stay open . . . maybe you mean the trunk lid? Probably just the shocks for the trunk lid. That was also a common repair
Here’s my recommendation
Either bring the car to the Benz dealership and hope the most experienced guy works on it . . . you want some middle-aged guy working on it, NOT the young whipper snapper who just “graduated” from UTI
Or bring it to a reputable and established independent shop who only or primarily works on Benzes. Even there, look for middle-aged guys, not youngsters.
You need somebody who’s had a ton of experience working on this specific vehicle