Access from engine compartment to passenger compartment?
 

I'd like to run a wire from the engine compartment to the passenger compartment. Can someone tell me where I can find an opening between the two, post pictures to help me find it, and explain how to get the wire through? (For example if it's hard to reach, what kind of tools I would need, or if I have to remove something.)

Re: Access from engine compartment to passenger compartment?
 

The way that it's generally done (in my experience anyway) is to poke a hole in the large firewall grommet/seal thing for either the engine or transmission harness and feed the wire through there. The transmission one is on the firewall beside the brake booster and the engine harness goes through on the other side.

I would probably go for the transmission side. Use a sharp pointed pick to pierce the rubber, squeeze the wire through (may have to poke/shove it to get it through), then go inside the car and pull it along. The interior side of that harness is above the gas pedal under the dash. Once you have the wire in place you can place a drop of silicon or RTV on the rubber to seal your new wire and keep engine bay fumes out of the cabin.

Re: Access from engine compartment to passenger compartment?
 

I ran a power wire for a sub through the transmission grommet, and I did not use RTV to reseal the slit I made in the boot. No heat leaked through, and I did not notice any smells either :)