Originally Posted by chops

its simple. remove the plastic cover covering the battery, as well as the part that connects to the windshield. you will see a black gromment where all the wires come through. you can choose to either unwrap the wiring or poke a small hole in the gromment and push the wire through. the wire will come out in the passenger side of the car right above the glovebox. shove a light in there and you will see it. ive done audio installs on many cars, and the Z was by far the easiest to get the wire through the firewall.