Car Stereo Wiring Diagrams
Below I have put together some of the best free sources for car stereo wiring diagrams and wiring colors. 
The first resource is best for finding the power wires for your car, deal more with wiring diagrams for car radio, It covers most makes of vehicle and has both stereo wiring diagrams and car alarm wiring diagrams
Wiring Diagrams – Security and is geared toward car alarm installation, Still good for finding the power wires needed to hook up your car stereo.
As for the rest of the trunk, there is a fuse box on the left side. The crossovers for the front speakers are on the right. 
The capacitor for the sub amp is hidden under the board that the amps are mounted to. This way, the distance from the cap to the sub amp can be kept very short.
Car Stereo Automotive Wiring Diagrams
