[Pampered-Z]

With a unit body car the bar/cage mounts to the floor pan not the frame, and with nothing going into the engine compartment the front subframe is not reinforce, likewise without bars going down into the trunk well you not supporting the unibody from twisting. Where in a a 10-12 point has a halo, front down bars, cross bar (under the dash) and bars that pass through the firewall to tie in the front of the car that makes it ridge. A 6-8 point bar is only to protects you from being crushed in a roll over or heavy side impact, what you want with a 10 second 130 MPH car. 9's and 135+ mph is 10-12 point cage. Under 7.5s funny car type cage/ Driver loops.

You really don't need to tie into the frame the way your thinking. look at the second pic, those bars are plate mounted. There are probably gussets under neither that attached the unibody to the frame rails, they don't actually pass through the floor pan. You have plates on both side of the sheet metal you brace off of.

Think ahead when you do your install. For my main hoop we used oversized plates so that if I ever need to we can add gussets to support the LSA mounting points into the cage. We also ran the rear bars into the trunk well. Again, we used plates that attached to the top of where the frame rails are and the plates turn down into the well. So if needed in the future I can add a cross brace for additional support.