The guys on the Mercedes forum seem to recommend only owning a Mercedes that is under full warranty new/used and get rid of it when you are running out of warranty. From what I could tell a lot of the problems are electrical and computer and they cost big/big/big bucks to fix and when fixed they don't stay fixed. Example SL's with bad wiring harness and it cost like $9000 to replace the harness
Really makes you want one real bad doesn't it 