Hey guys,
Just joined up. Have brought a cheap '96 Cavalier to use while my truck is off the road. The old cassette player and crappy speakers aren't going to cut it so I'm using some of the old audio gear I have lying around. Have 99% of the system figured out, but where is the best place to run power cable through the firewall? Only using 4g cable, so don't need a massive hole.

The is a HUUUUUUGE Rubber gromet in the Firewall, from the inside it is up and to the left of the brake pedal. Poke a hole and run as much wire as you want.

Where your wiring harness runs threw is a rubber grommet and you can use that, there is also some grommets on some vehicles not used ,you can also drill a small whole threw the firewall add a grommet and good to go