I'm installing my sub, and this is my first audio install. I have all the wires except the one to the battery all set, and I can't figure out where to pass it through the firewall! Please help.
-E

 

Remove the driver's fenderwell covering. It's the plastic piece where the wheel is that protects the engine of the car. Once removed, you'll see some wires entering the car's main cabin. Poke a hole in that rubber grommet and run the wire through there.

 

I would suggest avoiding electrical hookups through the fender well considering the 4th gen's have a grommet higher on the firewall near center of the car. Don't get me wrong, alot of people have gone that way, I just think the other is cleaner/safer.

Look behind your intake manifold just right (driver's side) of the center line. there should be a black plastic/rubber circle that just pops out. if you crawl under your dash you can see a small circle in the plastic liner behind the dash.. it doesn't line up perfectly but you can stick a wire in from the engine compartment and pull it though from the inside.

 

Thanks guys. I ended up hooking up through a gromett in the wheel well. It's the easiest, and I tend to do that kind of stuff.
-E