So far from what I can gather their are a few options to choose from. But the main question is: What is the standard connection on the back of THIS headunit: As far as I know its : ISO or Quadlock Its the standard headunit in a 54 Audi A3 Sportback 2.0TDI Sport. If that helps. Once I know the connection I can find what I need to plug in an MP3/USB. So far I've found a few products doing this (any views?) Dension Link Gatway 100 These Products from In Car Express - (not sure which one connects) http://www.incarexpress.co.uk/catse...essories&type=Aux-Input&fitment=Audi&limit=10 This eBay Product - http://cgi.ebay.co.uk/MP3-Player-fo...oryZ3293QQssPageNameZWDVWQQrdZ1QQcmdZViewItem This eBay Product - http://cgi.ebay.co.uk/MP3-MAZDA-6-M...oryZ3293QQssPageNameZWDVWQQrdZ1QQcmdZViewItem This eBay Product - http://cgi.ebay.co.uk/MP3-Player-fo...oryZ3293QQssPageNameZWDVWQQrdZ1QQcmdZViewItem Any help? Thanks!