Getting ready to order new 06 GT, here's my idea; order a deluxe, upgrade to leather seats, upgrade interior sport package. That leaves me with cheap stereo, but saves me $$. Now how would it sound if I replace the head unit and run 4-6x8's, I'm thinking Pioneer head unit with the best Pioneer 6x8's. Would I have to rewire anything, speaker wise? Then later on I could add an amp and subs if I want. Does anyone have a base unit stereo, how is it wired?