I just bought a 2003 Mach 1. It has a Pioneer Head Unit that is connected up to the factory amps and speakers. Sounds good, but I really don't like the deck. I want to go back to a factory head unit. Either the 6CD unit or the Single CD/MP3 unit. Does anyone know if these are swapable? I'm not sure which head unit was in the car originally, but some research seems to point to the 6CD unit. There are also a dozen different models of each of these. With the Ford part number the same except for the last two letters. Anyone know if they are compatible? All seem to have the same connections on the back.