CLK 55 Problem
Definitely do a search for a more thorough answer but here are some quick problems that I have noticed (personally and on the board):
1. Motor mounts
2. Window regulators
3. Rear tires (quick wear)
4. Mass air flow sensor replacement
5. Air conditioning controls (personal)
Other than that, my car has been a joy. Just got back from a long lunch with a good friend and had the top down back all the way to the office. The engine note is just divine and the solidness of the car is reassuring (W209 = 3900 lbs of German steel). Hope this helps.



