I had the same problem with my 300TE. The dealer replaced the mirror. It didn't fix it. I complained. The Mercedes area rep said it could be that the frame of the car was bent and had an oscillating tendency to it. A year later, when it became so annoying that I couldn't even look at it on a long trip, I took it off in an attempt to put some rubber tape to dampen it - I see the housing hanging by one screw. Tightened both screws and it is perfect now. So much for their expertise. I have an extra mirror if anyone want it.