Yeah, the one circle (or both if you choose) will be a parking light, brake light and flash as a turn signal... then the remaining circles will be brake lights and parking lights. The adapter is about $10-$15 I think (dont remember, been a while since I got mine) and has instructions as to what wire is what. They can be found at any auto parts store. The only wirring you have to cut into is the harness at the tail lights, so you're not cutting any wirring in the car. If it fails, you can always replace the harness.