[jyl]

Fogcity, there are various holes through the "firewall". I recently needed to run a cable from fuse block to under my dash, and found a hole by laying under the dash and looking for sunlight. There was one near the driver's side hood strut mount. I am told there are more on the passenger side.

I also installed a battery cut-off switch as thethrill mentions. It's not ideal as a daily anti-theft measure, since you have to open the hood to undo the switch, but when I leave my car in long-term airport parking it works. I think it's more useful for when you work on the car.