I chose not to have the standard CD Changer installed on my new Z3. Instead, I have the "business" class radio with a single CD Changer built into the radio. I have been looking for a non-BMW CD unit that I could install that I could operate through the radio (as if it was a BMW factory installed unit). Does anyone have any recommendations as to what unit I should get? I am "electronically challenged", so I would prefer a unit that plugs into the existing adapter in the trunk and does not require much additional work.