I'm putting a Car PC into my 2002 Merc C230 Coupe to play MP3s, XM, and do GPS. There's not much room to work with. I was planning on replacing the four door speakers with Diamond 6.5" and getting a 4channel amp under one of the seats (not much room there either). I have a self-powered sub in the hatchback. Since I've blown my budget on the PC, I'd like some recommendation for the speaker/amps around $1000-1500. My friend tells me to get the Diamond D3 400.4 to drive it. I'm dizzy after reading so much about all the possibilities, do any of you pros have some suggestions?