Wiring Firewall?
 

I've got an engine bay lighting kit on order and it should be here in a few days. It's a pretty simple install but the control box for the lights has to be mounted inside (i'm thinking somewhere underneath the passenger side dash). But to get to there wiring will have to go from the engine bay into the cabin. I believe I've found the two wiring firewall grommets (one on the drivers, and the other on the passengers right behind the battery) but they are already filled with tons of wiring that is very solid and won't budge, and I'd definitely be to afraid to try to rip all that out or even move it to make room. I know there is a firewall intended for aftermarket use, I've seen it somewhere but can't find it now, or maybe I'm just looking at something totally wrong. Can someone help me out here?

look at this:

http://www.ft86club.com/forums/showthread.php?t=6914

Perrin seems to have found a good spot to run some wires through the firewall, which is I think what you're looking for.

I found that, but there doesn't seem to be an opening in that side tube, unless you're supposed to poke one into it. But I don't think they'd design it that way

You are supposed to poke through a thin membrane inside this aux line tube Perrin showed you. You can do this with a wire or coat hanger-like piece of thin metal. If the harness already has a socket and wont fit through it, then you can either cut and reconnect it with soldier, or go the standard traditional way of drilling another hole and using a DIY grommet. :D