i was wondering if there are any existing holes that are in my firewall that i could run the wires through instead of drilling new holes?

 

well if your car has a cable operated Speedo, you can run wires through there with the cable. Or depending on how 'clean' of a job you want. you can follow the main harness down behind the passenger side fender. remove the fender liner, and interior kick panel. You'll find a wire block.. there usually is some available space there.. I ran a couple wires through there.. worked great.