Where to go through firewall

right now i am trying to install the power wire for my amp and i cant find a pre-cut hole in the firewall to go through.. I have a 2000 Mitsubishi Galant . I also have a 1991 accord..and the firewall hole was a piece of cake to find

ok on the passengers side theres a whole lot of factory wiring that goes through the fire wall. just poke a hole in the rubber and shove the wire through(i fit 4gauge wire through) after that you can pull up the door sills and put the wire under the carpet...