dahaker

Hi guys since this is my first audi I had a few questions. My car is a tiptronic fwd 1.8t, im getting some vibration only when i shift to D,R and any moving gear only in a stop. If I change it into N or P it stops vibrating. It does not vibrate while im on the move so I think its not the axles. What could this be? I checked yesterday the motor mounts and didnt saw any purple liquid around them or anything so i suspect its not the engine mounts. The guy i bought it from did told me he had replaced one of the transmission mounts because it was vibrating back then. About the rpm neddle when the car is in idle, i can see it(jumping) dropping but then going up a few rpm's like 800,790,780,790,800. and when i rev it somewhere between 1-1.5k the car shakes a bit.