That's really a simple install that you want & you do not need the harness. I would just tap into the parking lights (chances are you'll want the rest of your lights on when you want your fog lamp on) for power, & run it thru your rocker switch back to the JDM light.
Oh & I'm part of that "silly 4th brake light blinking" crowd, but i put a duel element holder so it functions as a fog lamp as well
