I'm planning on getting a custom roll bar welded in. It will probably be a 4-point rear cage since I don't plan to do wheel to wheel racing, only Time Trials, and I know Time Trials doesn't require a cage but it's a good idea anyway. I want to have the rear bars mount to the shock towers with an X brace between them. The main hoop will have a diagonal bar and a harness bar. I figured that if I end up doing wheel to wheel racing I can always go in and add on the forward bars later. I'm reading through the NASA CCR now so that I can make sure that the cage will be legal for wheel to wheel just in case. The cage will be 1.75x.095" mandrel bent DOM tubing. The main hoop will have no more than 4 bends and will be one continuous piece of tubing. The rear bars will have no bends. The mounting plates will be at least 3/16" thick. Etc, etc, all based on NASA's CCR. Anyone else already do a bunch of research on this?