long story, but someone was clownin me about a mistake i made when watching a vid. me i was use to grounding at the rear, but i noticed someone gounded all the way back to the batt and i ask why it wasnt gound and i was clowned because it was grounded at the batt but i never seen that i alwayz when to the frame.
its up to you the longest you have the big 3 you could ground the back battery in a good spot in the back or you could ground your back battery in the engine block where the front battery negative goes you could hide the wire under the car and just run it back then drill a small hole so like that you dont have two 0 gauge wires inside you car thats what im doing