I think you are speaking of the wing MOUNTING PLATE. I don't own a roadster to know for sure, but I would think it is not much different than the coupe. The coupe unbolts from the underside. Remove your trunk liner and see what you find. And remember when going back, be sure to properly reseal the mounting plate to prevent water from entering. Also you will notice orings on the wing studs when your remove the wing from the plate. Be sure they are back in place when going back together.