If your car has a frame the bar mounting points have to be welded to it. If unibody you can bolt the whole bar in with four 3/8" bolts through plates at each of the mount points that are sandwiched, or welded to plates on top. Swing out door bars are ok but the rest of the bar has to be welded, mig or tig. Thats why on that Mustang link posted the bar with the removable crossbar isn't ok for "sanctioned" drag racing and even says NHRA rules prohibit removable harness tubes. I believe IHRA is the same. How much they actually check at your track is another matter though..