 Turbo lag, turbo lag, turbo lag  The problems I have had with this car start with the fuel pump humming noise. The dealer replaced it twice. As of now no more noise. AC turns off when it feels like it. I live in florida & it get hot here so AC is a must but the A4 AC seems to have a mind of its own. I had a 1996 A4 with the same problem. Now to my biggest complaint. The 1.8t's turbo lag. Say you are in the middle of the intersection waiting for an opening. In the Audi don't even think about creeping in. You better have a big opening by the time you step on the gas and the car reacts its too late. 