Rather than design some "guides" I just saw the wingnut in my parts box and it was the right thread. I like the idea of adding a flasher to the circuit. The LED was an "extra bright" one from ebay, 5 in a pack. Its very visible. Watch where you drilll the hole, there are some plastic support webs built into the trim panel. Don't drill too close to a web so you will have enough room for the mounting hardware around the light. I don't remember which circuit I tied into on the back of the fuse panel, I think it was the one for my back auxillary light so it shuts off when the key is off. Used some nice cable cover to cover the wiring. Been three years now since I forgot and left the brake on.