im trying to wire the power my amp from the battery to my amp which is in the truck so is there a whole in the firewall that i can put the wire through or i got to use the one behinde the wheel?? thanks

and can someone tell me where it is

 

The one behind the fenderwell and front right wheel is plenty big enough to accept 4 gauge, and is fairly easy to access once you remove the wheel. I did it myself in about an hour the other day.

 

I am using 0/1 gauge for my install I am doing right now. I just went to Home Depot and bought a 1 inch hole saw and some rubber grommets. Its simple and easy to do. If you are using 4 gauge I believe you can use the fenderwell grommet like stated by the above person.