There is a fairly large piece of unobstructed sheet metal directly to the right of the brake booster. If you can get your hands on a firewall grommet, this is a great place to drill a hole, as the battery is on the drivers side of the car. There is a Tweeter car audio store near here that gave me one of those grommets...ask your nearby installer if they have one you can take. Just make sure you drill the right size hole; start with small bits and work your way up. Getting through is frustrating, as it's two layers thick. Finally, when you do drill, be very careful so as not to drill a hole in the brake booster (big black cirle behind master cylinder). Hope this helps...
