Hi , I am about to install an amp in the trunk. I would like to know where or how the other member ran the cable through the firewall to reach the battery.
Ran it under the body from battery to trunk. Under spare there was a plug/grommet, I drilled thru that, and ran wire thru there. Remove plug and drill thru. IIRC, gas tank is under there as well. They're not the best for sound, get another battery for the trunk. You'll destroy the alternator.