Seeing as I've only ever read the forum and used the information, I thought it was finally time to give something back.
For anyone interested, I've just removed my 6-disc changer, due to all the CD Error problems ('03 20VT), and replaced it with this:
www dot addacdchanger dot co dot uk / USB_Products /USB_kits_for_Factory_Stereos/Seat_USB_Adapter/Seat_USB_Input_Adapter_for_Factory_Stereo
I didn't want to change the head unit, but wanted easy access to as much music as possible. This CD Changer emulator seemed to fit the bill, is cheap and works really well. Very pleased with it!
I also like the fact that it has a USB and a 3.5mm audio in jack, so you can literally connect almost anything up to it.
Hope this helps someone!
Matt.
(had to obfuscate url as I don't have enough posts)