Help with running power line through firewall

Where would be the best place for running a wire though the firewall i have a 2002 impala and i found the gromet on the pass side but cant seem to get me through is there an easier way or am i doing somthing wrong?

I need to route about 4 gauge wire

there's a spot on the driver side where the cruise control wire goes. under the dash

http://www.impalahq.com/ ... If you go here and click on How To's there's one on running wires through the firewall. I can't post the link directly because they use frames.

Thanks alot ill check that site out