I picked up some cheap fog lights for about $30 and need help installing them.
Mounting and wiring was pretty simple but how do I get the wires through to the interior to the switch? I looked up oem fog light wiring and it looks like they come with a harness that you just plug in. These are just plain wires that plug into the switch but I can't find a way to get them through the firewall.

 

You will either have to snake them through the existing wire harness bundle, or drill a small hole and add a rubber grommet.

FWIW, to gain the most light from the fogs, make sure to use a relay. This way the power from the battery to the fogs is the shortest distance. Otherwise you will have ~20' of wires from battery>switch>light, and will have a voltage drop that will affect light output.