Where did you guys put your power wire through your firewall... I'll be taking the plunge pretty soon but it seems that the firewall might be the biggest pain of the whole install. I have about 18 feet of 1/0 awg sitting around but decided to go with 4awg for an easier install... unless there is some magic conduit for 1/0awg wire in the G
Forgive me for the rather common question but I didn't find any pics or threads regarding getting through the firewall. Any help is appreciated.

 

I removed all of the plastic that houses the battery and used the hole where the rubber cover is. afterwards make sure you reseal it with some silcone to stop any leaks or water from getting in.

 

There is a large rubber grommet under the battery cover near the top of the fire wall that is plenty big to slit and slide the wire through.

 

I resealed it with some high temp liquid electrical tape.

 

I didn't like the idea of cutting into the grommet, so I unwrapped all of the electrical tape that seals the wire bundle to the grommet, inserted my 4awg line, filled with liquid electrical tape, and then retaped the entire grommet. Can't even tell its not supposed to be there

 

I made a new hole down lower behind the battery and used a 0ga grommet for my 0ga run.

 

I went with the factory hole by the battery. Definitely reseal it because that's where all of the water from the windshield goes. I think I was the first to discover that while my ECU was taking a bath. That could've been bad.

If you drill a new hole make sure you know what's on the other side. That area is full of all kinds of expensive stuff.

 

All you guys have coupes? Is this grommeted hole in the same place by the batter on the 04 Sedan?

 

Yes, the 03-06 sedans have the same rubber piece. Make sure you seal around it with silicone after the wire is passed through.