There are two reasons why we decided to keep the factory TJ rear ’cage and add TJ parts to it. The primary reason is here, at the door surround. Unlike a YJ where the half-door top door surround is part of the top frame, on the TJ, it is separate. A pin goes through the tub, two hand-turn screws hold it to the windshield spreader bar, and it needs to hit the windshield at the right place. The side windows, top, and to a degree, the windshield header bar all require this to be in the right spot.