1994-1995 c280's have a terrible problem with leaking head gaskets. Replacing head gaskets will cost at least $1000.
I was fortunate enough not to buy a 1995 c280 and decided to get a 1994 c220 (no head gasket problem), but now its transmission is dead at 123 Kmiles. I think if Mercedes were able to sell 1 million cars per year in the US, countless class-action lawsuits (triggered by people like YOU :-) would make Mercedes go bankrupt in no time flat.
As M.B. DOC said in some previous post: "Mercedes dropped their ad"s "Engineered like no other in the world" in the early 90's."
Recent Mercedes cars have a reliability rating of 1980's Huyndai Excel IMHO :-(