Hi guys new here and new to owning my EL Fairmont Ghia.

its got the premium sound system with the amp in the rear and the DSP upfront.

My question is:

if I swap the head unit will the stock stuff all be wired up normally with regard to the amp sub and speakers.

Just wanted to check it wasn't hard wired or if any trickery is involved.

I was gonna buy a cheap cd head unit with aux in / mp3 etc

(saw the DIY Aux in thread and thought that was great idea but my volume knob is stuck going down both ways)

Do I need to make sure it has anything specific to ensure all speakers and sub run off the amp into the unit?

thanks a lot total noob