Behind the leftmost panel in the trunk (the one that covers the fuel cut-off switch) there is a computer module, I think it's the keyless entry. Anyway, I've grounded to the factory spot there with 0ag and had no problems. I've also used the seatbelt bolts (Torx 55 I think), and it's the BEST option, but the other one I gave you is easier to hide the wires behind the panel.