I just received the CD changer I got from an EBay auction for $175.00. It was a never used demo. Works great and took all of 5 minutes to install in my 2000A4. There was another auction for the same Panasonic changer at about the same time and that one sold for about $215.
So if anyone's looking for one, don't forget the auction sites.

I did the same for my '96. Scored the original equipment piece for $280 (vs $529 from Clair). Definitely worth trying if you can save some major $$$.

And for the record, it came with a bracket that didn't want to fit anywhere, so I've stuffed it in place of the tool kit. Put the tool kit with the spare, and folded the little piece of trunk liner under. No muss, no fuss.