CD Changer Question
I'm thinking you'll find that it makes sense ($$$) to go that way.
JMHO!
the factory head units "changer control language" is proprietary; so no... you can't easily swap in another mfgrs changer.
At one time there was a single model Pioneer changer that would directly swap in place of the factory unit - but that was because Pioneeer built the one used in the C5 to begin with. So you weren't getting any better quality by doing so.
you can get an aftermarket changer to play through your factory head unit & speakers, but you'll need to mount a control-head to operate the changer (as the buttons on the head unit won't work).
When playing changer CD's with this setup, the only thing that works on the head unit is the volume/tone controls.
I went with a remode mounted MP3 player (has a 20g internal hard drive) and piped it through the factory radio & speakers:




mounted the control head in the center airduct:











