I think building any audio system into your panel may come back to bite you.  That technology is moving so fast.  An AUX audio input might be the best way to go.  I built a CD changer into my baggage compartment.  It seems like a dinosaur already!

 

My kids have iPods with thousands of songs loaded.  Sirius radio seems to be the best bet right now, but who knows what's around the corner.

 

Mike (never has a shortage of opinions) Easley

Colorado Springs