Built from heavy wall 1.75" diameter tubing bolted to the 6 factory hoop anchor points these bars are a serious upgrades from the stock NC equipment. The factory cross brace is reused, no complications with remounting OEM accessories. Plastic interior panels are easily reinstalled and no alterations to the stock seat belts are required. The M3 Sport shares the same main hoop as the M3 Hard Bar and the attachments to the 6 factory hoop mounting points. Additional support is provided by 2 rearward braces w/ large 3/16" mounting and back-up reinforcement plates anchored with grade 8 bolts and self locking nuts. Note: Because of the rearward braces, the M3 Sport is not compatible with the retractable hard top. See Hard M3 Roll Bars for PRHT NC Mx5.