damacman said:If you're installing an ordinary power amp in the trunk of your 'stang, then do your best to find a nice flat piece of metal that doesn't have 6 spot welds between it and the body. Scrape off the paint and VERY securely fasten your ground connection to this area with a silver or gold screw -- do not use black or black oxide screws. [It goes without saying to check under your car before drilling holes in it!] After tightening your connection, attempt to wiggle it -- it should be wiggle free.
damacman said:I did not use the word plated, was just trying to caution against using black or black oxide screws that have high surface resistance. 302stang's advice on upgrading the return path from the alternator is solid. I prefer all ground upgrades use the frame as a connection point, and not the chassis.