I will make a guide on installing a subwoofer/amp for you guys tomorrow since i don't have any work tomorrow, well... no promises.
The hard part for you is deciding where to install the pioneer amp, and running new wires to the 5X8 Speakers in the front.
If it were me, I would run 4 preamp wires from the headset to the rear seat on the left side and the 4 gauge power wire to the right side along the remote wire on the right side. 3 preamp wires (be sure to remember which is front/rear/sub) will be connected to all preamp outputs on the cd player and the fourth will be connected to your factory harness for the factory subwoofers in the door. As for the amps location install the subwoofer amp on the back of the right seat and the speaker amp on the back of the left seat. If you get it right, you should be able to fold down the seats with the amps installed. Then run the fourth preamp wire to the alpine amp's preamp out. I hope this makes sense.
Then you will have to run speaker wires to your 6X8's, the doors will be the hardest.
As for a ground, take the rear seat off, drill a hole, sand it, and use that. I was able to find an unused screw hole under the seat!
To get the power wire in, there is a hole you can use under the battery. The battery cover screws are threadlocked but it can be taken off. Make sure you use a grommet for the firewall!!!
Oh. and don't try hooking up the factory speakers (the four 5X8s) to the pioneer amp!!! You will blow those speakers and then you will have to get some infinity speakers.
