It's been a while since I was last here, but I need a bit of advice if you can. My 2.0TDI has been excellent - now on about 45K and coming up to 3 yrs old. I noticed a few months ago that when I was driving at speeds of around 60 - 80 I would feel a definite vibration as I accelerated. It felt really odd, like the flywheel was off balance. The engine revved smoothly and there was no jerkiness, just this vibration. I notice it most around 60 and in 6th, a definite juddering which lessens as speed increases. Also feel it in 5th, but hardly at all in 4th or any other gear. Thought it might be linked to revs (about 1900 seems the hotspot), but not sure. To cut a long story short, Audi had the car three times and fitted a new flywheel and clutch (which apparently had turned blue), fitted a new OSR tyre (apparently I had a large nail inside which was causing an imbalance...), and also spent a week with it doing not very much. None of these sorted the issue. Each time they had the car for a week and gave me a courtesy car - last was an S-line A3 (nice) which was brand new... I could feel a similar vibration, albeit extremely weak, in that. My guess is that there is something out of balance, but can't imagine what. Last time Audi had the car they also tested other cars with the same engine and similar mileage. They found all, including an A4, had the same vibration. Anyone heard about this? Any thoughts as to what might cause it?