My A6 3.0 TDI has the good old lovely prop plane noise and having done some investigation, it's the front nearside bearing. I had to have the offside rear done under warranty at 44000 and now at 57000 this one has gone...unfortunately the car is 20 days out of warranty grrr! What is the chances of getting any goodwill gesture out of Audi given it has full dealer history and if so, am I best having a whinge at Audi CS or the dealer? I am a bit annoyed about Audi bearings...they seem to be made of chocolate! My A4 had to have both front bearings at 90K and now two on the A6. My BMW did 210k miles and was still on the original bearings with no issues when I chopped it in.