have you considered an MP3 player? you can plug one into the back of an older blaupunkt or becker with a simple DIN plug adaptor cable (available from becker north america). the adaptor would sit in the glovebox. that way, you can have 1,000+ songs on tap and you probably wouldn't have to change the head unit. IMHO, going digital/MP3 makes the idea of a CD changer seem obsolete.