So the next G6 is a 4 door. The front doors hold 6.5" speakers and the rear deck, 6x9's. Because it is a lower model to the GT I have, the door speakers and radio will be much more simple to upgrade to aftermarket gear. I may still have to do the retained accessory power thing for the head unit but that is easy enough to handle. I think I will just go old school. Components up front, coaxials in the rear, subs and two amplifiers.