Okay, im redoing the entire sound system in my 01 GT, heres all the parts
Kenwood Excelon KDC-X994 Stereo, already installed
Polk audio DXi 4 inch coaxials and 6x9 inch 3 way coaxials in the rear deck
Polk db 5.25 inch components in the doors and polk DXi 6.5 inch components in a set of Q-logics kick panels
2 RE audio SEx10 D4 Subs
Subs will have a custom enclosure built by a trusted audio shop with a world championship in DBdrags
2 Polk 600 watt 4 channel amps for speakers
1 MTX jackhammer jh1200 amp for subs
1 Optima Red top battery
1/0 gauge from one battery to second battery
4 gauge to the amps
12 gauge to the speakers and amplifiers
Big three upgrade with 6 gauge, and a pile of hushmat, im getting 58 sq feet for 180 bucks
The car has the factory bose speaker and amp option

1. I should be sitting at around 1800 watts rms total, but i dont think the grand prix can handle that, should i use a capacitor, a second battery like i have planned or a bigger alternator? This is the most important thing i need to know

2. When i run the new speakers and subs from the pre outs on the back of the headunit what do i do with the stock speaker wires and the stock wiring harness?

3. Where should i mount the crossover blocks for the components, im debating under the seats, cause i really dont want to put them in the doors

4. Is there anything else i should know before i do this, bad wiring, rap, ground points, etc....

Thanks for any help you can give me, ive already got the speakers and im buying the rest in the next few months, so any help is appreciated