where it meets the plastic, there is a bar that goes down and mounts to the body behind the panels. a hole has to be cut in the panels for the bar to slide in, and 2 more small ones in the side to access the bolts (hidden when door is closed). I am pretty sure it adds some structural support as it is basiacally a “strut brace” for the center of the car, but in no way is it a safety item like a roll bar. I would say its more for looks, but probobly adds a little strength.