there was like a ground wire comming out of the top of the gas tank... i guess to get rid of any static electricity? but i just didnt hook there just to be on teh safe side.. that car was a bitch to install tho. its one with all that dvd navigation crap in it so u cant pull teh head unit out or an ythign like i normally, i hada go to teh fuse box for the rem wire cuz the cigerette liters required me to take off teh whole center concole thing...power wire was a bitch to get threw the fire wall... owell it all sounded good in the end.. it was a w3 with a profile amp... it actually slammed pretty good, i was impressed..