[Firewall] This part was honestly the hardest part. You will want a friend to help you for this. So here is what I did. There is a hole with a rubber grommet right behind the brake pedal. Take the grommet out and drill a hole into it with your Dremel. Make sure to cut it just a tad bit smaller than the 4 gauge wire to help make the wire seal better. Here is the tricky part, essentially that hole leads to a box, that’s right a fkn box. This box has one hole in it, but it is clearly visible by shining a flashlight into the role. It is directly to the right when your inspecting the hole from inside of the car. So this may sound ghetto, but I took a BBQ Skewer and pushed it through both holes, pointy end first. I had my buddy with me to assist me with the next step. Get your power wire and feed it down to where the skewer is poking out, hold an end up to it, and have your best friend push hard to lodge the skewer into the power wire. Now carefully bend the skewer 40 degrees in order to push it through the first hole straights. Otherwise you will be trying to push the hard wire with a 4gauge wire into a hole at an angle, which is impossibly, do the physics Im right. Once you get the wire through make sure your buddy is still gently applying pressure so that your wire does not slip off. Gently and carefully feed the wire through the hole and have your friend pull it out from inside the cabin. Tadaa!! No run your wire all the way to the trunk along the driver side floor trim panel. Hook up the wire to the battery, try not to unplug the battery if you do not know your Head Unit code (My code was on a sticker inside my glovebox. However, I did the entire install with the battery plugged in. (DO NOT PUT FUSE IN UNTILL YOU ARE COMPLETELY DONE WITH INSTALL).