Was flipping through some back issues of SCC and found the mod that allows the fog lights to be on even if the high beams are on. I do a lot of mountain driving and would like to be able to project as much light as possible while I'm out.

The pictures and description is clear enough, my only question is what gauge wire should be used.

Here's the link:
http://www.sportcompactcarweb.com/projectcars/0209scc_projwrx/

What do you guys think?

The gauge of the wire isn't important, it's low-current wiring for the relay and switch, not running the fog lights directly.