One problem related to tire sidewall has been reported for the 2009 Mercedes Benz CLK320. The most recently reported issues are listed below.
When inspecting my tires at 19000 miles, I discovered cracking along the inner sidewall for one my four tires. This is the only tire showing any cracking. I took the tire for review to the tire dealer, and their expert indicated this was indeed a defective tire, that the cracking was not yet detrimental to the tire, but that is should be replaced as soon as possible.