For those of you contemplating installing an aftermarket CD changer (for example, the roughly equivalent Alpine 601) in place of the somewhat overpriced Audi factory unit, this is for you.

The main problem with using an aftermarket changer is that the wiring harness works only with the Audi unit, and no one yet makes an wiring adapter. Note that this adapter cannot just be a simple connection-converter, but also needs electronics to supply the correct handshake signals between the factory changer and head unit (the Delta Radio/Cassette). A company called PIE specializes in wiring adapters for factory CD units and they have been promising an A4 adapter for many months now but the delivery date keeps slipping. Last quote was for delivery in "Q1 1997" but I still haven't heard of one being available at time of writing. Once they are available, you will need to get one from your local aftermarket auto sound store as PIE does not deal directly with the public - estimated cost for the adapter has been in the $70-$100 range.

Although the cost for the aftermarket solution is around $350-$400 (for the changer plus the adapter), don't forget the hassles of installation and hole-drilling that a none purpose-built unit entails. Although the factory unit generally goes for $595 (plus another $25 for the bracket), it is very simple to install, comes with the Audi rings on it, and would be covered by the 3 year Audi warranty if bought with the car (opinions are mixed about whether this applies if bought later - but you could probably fake it if there was a problem down the line!). The other big advantage of the factory changer is that it is available now (unlike the wiring adapter at time of writing), plus you know it will provide full changer control from, and integration with, the Audi head unit.

Another option is to use an RF-interface aftermarket CD changer. This also has the advantage of being available now, but many disadvantages: you need to wire a controller unit from the changer at the back of the car to the dash; the unit would not be fully integrated (you have to 'tune' to a radio station to listen to the CD); and audio aficionados will tell you the sound quality is not nearly as good.