S3 autochanger, replacement

Change the HU. FM Modulators are sh*te, the standard HU is sh*te. Buy a new HU that has an Aux in for MP3 players.
The Audi HU is standard DIN size, it is just the fascia that is wider and there are plenty of fascia adapters to fill the gaps.

Sanityclause, email or PM me if you'd be interested in selling your audi changer

there are kits available to put the sony 6 disk mp3 changer directly to an audi head but there are problems - mostly because you can only increment the tracks one at a time, and only upto 99 tracks

each mp3 cdrom can hold a lot more than 99 tracks, but you cant access each separate mp3 music cd, only sequencially go up or down the track list.

once you get past disk 99 you have to let the rest just play sequencially which may or may not be a problem.

the phatnoise mp3 system is a hard drive system specifically designed to work with the audi head units - it gives voice readings of your choices and changes the 6 cd disk buttons of the head unit to be able to choose artist, album, playlist etc as well as allowing track up and down, all with the standard head unit. have a look at www.phatnoise.com - you can buy these from audi dealers or ebay

as for the replacement side panels for filling out the facia - I've heard that the seat leon has the same dash?? (and certainly cheaper!)