I also noticed that the W210 wagons rode kind of hard in a way. I think you just have to live with it. I don't know of any way to adjust the dampening. When I was a dealer tech, we didn't see any problems with those systems, only the AirMatic suspensions on the W220 S-Class. Those had pump problems thanks to DC's brilliant engineers placing the pumps where they could suck water in and hydro-lock themselves.