Read a post where someone was concerned about getting a driver out of car w/ a halo on top cage, not sure what someone meant by halo? We race w/ a driver that's added a 2nd loop just like top of the cage to give him more head room & it bolts to wing mounts. As far as getting a driver out of a car I saw a safety crew use a wrecker which I thought was weird but worked & driver was ok But yes I like to see at least 3" minimum for head clearance from helmet to top of cage, 4" is better