Yesterday I installed a power line for my N20 (amongst other things) and I ran the line through the firewall on the passenger side.

It's a piece of cake.

Look under the passenger side (up under the glove box), there's a bright orange or red cable, near that there's a BIG rubber grommet. That grommet is prolly 2 inches tall by 3 inches wide. Make a hole in that (a small hole), and force the wire through. If you can get it forced through a small hole, it should stretch it and seal it off from any weather problems.

It comes out right under the battery. Just force the wire through, look down under the battery, reach down and grab the wire, and pull to needed length.

There's also a post on the battery for any external power you want to draw off of it. Looks like it should be good for a fairly large wire (maybe 2 or 1 gauge).

 

For those putting a sub in the trunk I would suggest putting sound/vibration material over the side maker lights on each side of the rear of the car. They rattle like a bitch. I stuck it over the inside with the sticky tar stuff and it took care of the problem. Also the black cover holding the light and truck latch vibrates as well. I stuck rubber inbetween the trunk and the black cover to stop the rattle. I still get a little but it can't be heard inside the car. I'm running two 10 inch kickers in a ported box. It's a damn tight fit in the trunk. Mine is a convertable so the truck space is much smaller.