I decided to run a 0 gauge ground wire the length of the car and then have it hit 4 busses like the one in the picture below. At each of the junctions, one wire would ground the system to the frame and another would run over to the smaller buss to ground anything installed on it.
I did this at the front of the car, the firewall, the back seat wall and the trunk area. There should not be a lack of a good ground!