Just got a brand new 2009 c300 Sport Sedan. The car drives great. However, when I engage in gear (D, R, etc.), the car vibrates. It seems that the vibration comes from underneat the car. Does anyone else has the same problem?

 

I also have a 09 C300 Sport, just reached 1000 miles on it. Since reading your post I have paid attention for about a week. I have not experienced any vibration...better safe than sorry..send it in for service.

 

Maybe an engine or transmission mount isn't working as intended? Or, if you hear a rattle, a heat shield?