I have a 2000 A4 and i am getting 3 beeps when i am shifting into different speeds. It does not happen on particular speeds and it does not happen all the time. I can go for a while with stop and go traffic and no beeping. Other times i can be starting off in 1st and the car will beep, 2nd no beep, 3rd no beep and then it will go again in 4th. What could be causing this beep?