Reddit mentions of Allstar Performance ALL11040 Step Drill Set - 3 Piece

Alright, First thing is first. The firewall is the think sheet of metal that separates the inside of the car, from the engine bay.

First thing is first, look at your firewall (The back wall of the engine bay) and try to find out if there is some way to run a thick wire through there.

Look for rubber seals that already have wires running through them.

Also note, you want to run your power wire on the same side of the vehicle as the battery. So if your battery is on the drivers side, you want your power wire to run drivers side. Passenger side battery means you run your power wire on the passenger side of the vehicle.

If you do NOT have an easy or reasonable path to run your power wire, then you drill. You drill CAREFULLY! If you make a mistake, you can end up costing yourself thousands of dollars in damage from 1 little mistake.

Easy way to know where to drill is to use your eyes! LOOK at what you are drilling before you drill! DO NOT DRILL THROUGH SOMETHING IMPORTANT! Use things going through the firewall as guides. If your throttle cable runs from one side of the firewall, and it has a spot above it that looks good to drill, make sure to look at the opposite side of the firewall to make sure you're not going to hit something.

Once you have a hole, use a grommet! (some sort of protective device, rubber or plastic) so the metal doesn't shred the power wire's shielding.

if you're unsure, then drill a pilot hole first, and poke a coat hanger or some kinda rod through it first, if it clears, and you can see that the other side is clear, then you're home free!

I use a step-bit set that looks like this! http://www.amazon.com/Allstar-Performance-ALL11040-Step-Drill/dp/B003BZR1Z8/ref=sr_1_17?s=industrial&ie=UTF8&qid=1448935934&sr=1-17

Good luck!