Look the easiest place to throw the wires through, in my opinion is the following:

(i actually figured this out right before i actually ran the wires. The person who installed my alarm ran the alarm cables through here.)

If you look under the dash, right under the steering wheel is a rubber boot that is connected to the steering column. Pierce a small hole in the boot and run the cables through there. This way is better due to the fact that this opening to the firewall is only about a foot and a half from the battery. the rest is a breeze.