One problem related to service brakes has been reported for the 2000 Audi S4. The most recently reported issues are listed below.
I was on highway 93 north going 60 miles an hour when I suddenly I had to brake hard and as soon I hit the brakes my rear brakes locked in and I almost hit the car in front of me I had to release the brakes and change the lane to avoid hitting the car in front of me I went home did some research on-line and I found out from on-line forums and other websites that everybody who owns Audi S4 2000 have same problem this is a very big safety issue and there should be not just a recall but Audi should bee sued for making a car that would and will kill people.