I have an Audi A4 avant estate 1998 and it has the gamma radio cassette that I believe can also control a cd changer. I have found a round connector in the rear cubby hole that I guess is for the cd changer but it only has eight pins and a screen as opposed to the 13 pin connectors that seem to be on all the cd changers i have seen advertised. I have seen some gamma cd changers for Volkswagons but i don't know if these are interchangeable with the Audi and they seem to have rectangular plugs rather then the round one found in my car. Any light shed on this mystery would be very much appreciated.