There is an oval shaped grommet on the driver side about 8 inches in from the computer wire plug, is pretty easy to see unless you have a ton of after markets in the way. There is some rubber plug that fits in the grommet, that I was able to pass 2 14 gauge wires through sort easy; would of been real easy with a snake, but even without it was doable. Just take a ton of tape off and pull the existing wires out into the engine bay until you see the sneaking tape that is hidden right in the middle of the grommet, then remove that tape too. Slide your wires in the bunch and pull it back into the cabin. You could remove the rubber plug and pass just about all the wires imaginable through too, if you need that much space.