Two problems related to radio/tape cd player have been reported for the 2000 Audi S4. The most recently reported issues are listed below.
The cup holder in the dash board is very badly located, just on the top of the radio and other equipement. If any liquid spills from the cup holder, as it did on my car, the liquid would directly fall on the radio and the other equipement, and could cause a shortcircuit ( as I did). The radio blew up and the heat and a/c works when they wants to. So for me the cup holder has no use since the location is too dangerous. And I think vw has the same cup holder location problem. Dt.
The radio had really bad reception, cd and tape were fine. The reception only work for some reason ( but not that great) in the area where the Audi dealer was. The first owner had Audi put a new radio, but it took them 16 months to received the new radio. That is 2 months after I bought the car form the first owner. The radio was changed but with the same result. The dealer said something it happen that the radio does not work in some area, and that it was normal. ( as if I didn't know how a radio worked) I even talked to the manager of the Audi dealer, and he said the samething, so until now I'm driving a 40. 000 dollars car with no radio, how funny is that! dt.