Hi we have a 2009 c300 and have tried three different phones, they will connect to the car, make one good call, then the next call I can hear the other person on their phone, but they can't hear me from the car. First time we took it to the dealership they kept saying it was the phone, HTC touch, we tried a friend's iphone sameand had the same problem. Got a motorola android still hvaing the same problem. Took the car back to the dealership, said it may be the head unit and have one on order. Anyone else having this problem? Maybe a suggestion to try while we wait for the part?