I know "X" type lateral - kidney & hip bars are all approved and many racing groups only use them.......NASCAR bars sure look good at times when there is an impact like this...
http://msn.foxsports.com/speed/video/video-courtney-premat-involved-in-horror-v8-supercars-crash/
Horrible crash... only thing worse would be to have a T-bone instead of the side-to-side impact in this case. It would be interesting to see what conclusions are made from the crash in terms of if the car/cage/safety equipment did their job and if there is room for improvement.