Heres me living vida loca with no helmet, no fire suit, no cage no harness. Just jeans and a t shirt with stock seat belts. I'm big believer in understanding your cars capability and your own capability as a driver. Not every track event is you putting car at 100 %. And there are more scary scenarios on public streets quite frankly than any real danger in modern car on fairly safe track if you drive car within limits. And I pick my track events very carefully. Always low numbers with very experienced drivers who value safety and their cars.
Vette on Spring Mountain - YouTube
I have logged thousands of track miles over past decade without a single incident. Frankly speaking I think most people are worse off with cage in street car on the track than to drive cage less. To be truly safe in caged car you need proper winged seat, proper 6 point harness with Hans, seat mounted low in the car to clear over head cage elements, proper nets and very well designed cage,