Well I just bought my first Audi and I could not be happier. Its certified Pre owned (if that means anything) A5 Cab. If you drive the car then stop, put it in reverse and back up it makes like a loud pop or if you broke a large stick sound. Also from the passenger floorboard toward the front you can feel a wobble or vibration. The car is still under warranty just looking for any thoughts as to what it could be. Thanks.