I've got a 2003 Golf Mk4. At the moment, it has a VW Gamma Head Unit & Single CD player up front. I'm hoping to swap these two out for a VW MFD Nav Unit at some point. If I did that, I'd lose the CD in the front for a TeleAtlas Map Disc, which isn't musically that interesting(!), so I'm looking to put a CD Changer in. Not sure whether to go for a VW one or a random aftermarket one (to save money, it'll probably be off ebay anyway!) - but it would need to be compatible with the single cd player attached to the Gamma atm - all i have to do is hit 'select' and it alternates between the single unit and the changer. I've had a route around the boot of the car, and I can't find the pre-wiring - I'd've thought being a fairly late Mk4 that it'd've been there - does anyone know otherwise? Or could someone point out where I should be looking? Thanks for any help!