If there is an auto-reverse function on the radio, turn it off.
Second consider a hardwired solution like the Dice.

 

Sorry for bringing back an old thread, but after searching, it seemed like the most relevant place to ask this question. Does anybody know if it's possible to disable the auto-reverse function of the factory (Symphony II w/in-dash CD changer) stereo in my '02 A4? I'm having the constant reversing issue with a tape adapter, and the manual doesn't seem to offer anything helpful.