The D rings do have a flange that the rings stay inside of, and they do not have a point to bolt the flange (I would have to make a flange myself if I were to bolt them.) Also these would be permanent, the front ones would require the bumper to be cut out around the frame and the flanges would be attatched to the front of the frame(bumper mounts to the side of the frame) and the rear ones would be attached to the reese hitch, and become permanent also. The idea is to keep the Bronco safe enough for the road but use it mainly for an off roader or tow vehicle for the car trailer. thanks for the opinions.