The pictures Manny posted are of one of Shannon's cars, I don't remember which, but mine and Dustin's are pretty much the same so here's some more info
Optima Red Top Group 35/720cca
In the trunk towards the left rear wheel well area, cut holes in plastics with rubber grommets to make it look neat (like Manny's picture above)
Optima battery tray--search it on ebay
Rockford Fosgate battery terminals (up to 4ga cables only with just one additional input for accessories)
4ga power cable, Shannon has 2ga cable but 4ga is smaller and is just fine plus easier to run through the car
Route the power cable behind all the plastics, under the door sill, through the firewall/steering boot to the engine bay.
Ring terminals from Autozone, attach one to the end of the 4ga power cable that was run to the front of the car and remove the stock positive battery terminal end and put the other one on that end, then bolt them together for easy disconnecting from the harness.
Ground cable goes directly from the battery to the chassis. Dustin's ground cable goes from the battery to the chassis between the tail lights and from the stock negative terminal end in the engine bay to the transmission ground point using something like this, with one end cut off and stripped to go into the terminal (only black because it's negative).
I have the same setup but with an additional ground cable from the negative terminal run alongside my power cable to the engine bay and bolted to the stock location on the transmission, then from that ground point to the stock chassis ground point in the front.