Well I finally decided to upgrade my vehicles power and ground situation which lead me to research methods of grounding, how some other vehicles are grounded and how the extreme car audio guys are grounding their vehicles. Then examining our grounding system in stock form which appears to be very inadequate unless you have a carb car with manual Windows, locks, no air, manual seats no real stereo, etc.

I upgraded the main ground lines and then saw that apart from the thin metal of the roof, firewall and core support area our front, rear, and sides of the subframe are not connected together very well and would introduce much resistance and length in a grounding system. If you have properly welded subframe connectors this should be lessened though, correct? But none the less, is the answer to run multiple grounds ? A ground wire from the front to back and side to side and then grounds between the door and frame?

 

This video helps to answer the question of the best way to ground our cars.
It does show that there is less resistance using a 1/0 cable over the chasis but it may or may not be worth the cost involved. I would be very interested to know the resistance rating between the battery and the rear shoulder belt and lap belt mounts on a car with and a car without subframe connectors. I do not have my connectors installed as I need to replace the floor pan first....