allright i have a hi out put alt, and 3 yellow tops, all 0 gauge. with the added 4 gauge from the alt. bigger ground strap for the motor. but where o were should i ground the amp and yellow tops in my trunk cuttently im at a thick part of my body pannel

The vehicles frame.

Make sure you wire brush the frame down to bare metal and seal it up afterwards.

so brush the frame and tap screw it or have it welded on? and paint it after werds

wire brush or take some heavy grit sand paper and remove a patch of paint to where you will be locating your grounding point. try to locate the frame of the car and use it as a grounding point.

what i did for grounding my red top was i drilled a hole in my tunk right next to a frame like bar(my cars a uniframe) and grouned it there. after screwing in the ground i spray painted some rustoleum on it. in the pics are before re-painting. the ground cable is less than 2 ft long.