I've got a strange vibration above 50mph on my 170 Quattro. I had a rear wheel bearing diagnosed as being worn so that was replaced which quietend the vibration down and Audi also diagnosed the n/s rear wheel as being out of shape. The vibration is like a slow pulse which can be felt through the footwell and the accelerator pedal. The vibration lasts about 2 seconds before starting again. Ive also noticed that it gets worse under hard acceleration and when going round right hand bends. Could it be another wheel bearing, engine mount? Either way it's starting to drive me mad! Or could it be that wheel? Would it be worth swapping it with another wheel on the car to see if the vibration changes?