Where can I run wires through the firewall in a 2001 Ford Explorer Sport?

I have a 2001 Ford Explorer Sport (Not the Sport Trac just the regular Explorer.) I am wanting to hook up a amp and have to run wires from the battery to the amp located in the back. I am having trouble finding a hole in which wires already run through and into the engine. Is there anywhere I can run wires from my amp to the battery through an existing hole in the firewall?Where can I run wires through the firewall in a 2001 Ford Explorer Sport?In addition to rubber grommets in the firewall check the front door hinge area. I have a Ranger, I ran the wires for the amp through the fender to a rubber grommet in the body at the front door hinge area to feed the wires into the cab.Where can I run wires through the firewall in a 2001 Ford Explorer Sport?there should be some rubber grommetts you can squeeze them through