Thanks a lot for your response, Mike. I WILL show it to another mechanic - actually, this one is a shop that specializes in European imports, especially benzes. SO I thought they would know the car. And they might be right, its just that I would like to make sure there is a problem before getting it fixed.
Is there any way I can detect the problem (like steering instability, etc.?) - right now the car feels totally normal to me.