you should really be considering putting the empeg in its intended location, replacing the factory radio.

Ummm, Tony... you need to re-read what he said:

I don't really want to lose my factory stereo, because ... the head unit is the interface for many programmable features of my car, including the key fobs and tire and oil monitor system. Plus, OnStar also interacts with the factory head unit.

I think he is pretty much committed to retaining the factory head unit -- he will give up too many things other than sound if it goes away.

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"