I've just recently picked up an A4 B6 Auto, and having run it until warm (approx. 20mins), I noticed a strange judder feeling, not far from that you get when wheel spinning and it's jerking and gaining grip, when pulling away. It didn't happen every time, just some times. Once it had got up to speed (over 1500rpm or a higher gear) it seemed to go away. Now, I'm not afraid of the search bar and I did a bit of digging last night, and I've seen a few possible problems, worst of which is that the automatic transmission is kaput. The only thing I'm hesitant about AT failure is that, when I pulled up to some lights after the drive, I was in 'D' and I could feel a sort of surge through the brake pedal and the revs were bouncing round +/- 100 rpm of idle (~900rpm). I put the car into 'N' and the revs dropped until almost stalled, and then picked back up again with a few taps of accelerator. The last 10 minutes of the drive home were uneventful. I don't know if this is the dreaded AT fault that I've seen so many have, or if anyone has any ideas on what it could be/cheap places to start? I'm kind of putting the blinkers on now about the transmission being at fault because of what happened when I put it in 'N', I can't see how that would link to AT issues. It might also be worth noting that there is a constant quiet whine whilst under acceleration, I don't know if that is of any use? Any help would be duly appreciated. Cheers, Spat.