I just talked to the dealer again and they are telling me its an exhaust drone and that MB is having the same problem. Something about the note coming out of the exhaust. I said funny I can't replicate this standing still with RPM's they said it's possible. I am so irritated. They told me Chrysler is aware and dealing with it and there might be a tsb within the next 3 months. I am so pissed off I'm just ready to sell it for what I owe.