I suggest trying to feed it through an existing grommet if you have one thats large enough and has the extra room. otherwise, drill one a few inches from one you can see clearly, both under the hood and under the dash, and run out to AutoZone and purchase a few grommets to stick in the hole. You get about 3-5 for 2 bucks. Remember the size of the hole you drill so you can buy an identical grommet. You don't want any jagged metal edges scraping the wires, they will fray over time and cause a short, or even worse, a fire.