C6 Amp power wire
There is a rubber grommet on the firewall behind the battery in the engine bay. You can run you wire through the grommet. I pushed a coat hanger through the grommet from the engine bay into the passenger compartment, taped wire to the coat hanger, and then push / pulled the wire into the engine compartment (my dad helped). My 4 gauge power wire runs alongside the factory harness. Silicone lube should help pull the wire through. When you remove the battery you should see the wire harness going into the grommet. There is electric tape around the wire harness that you will have to remove and eventually replace.
Some people poke a new hole in the grommet and others drill a hole and install a new grommet.





