Originally Posted by Shamu

I'd agree in general but depends on type of events, tracks and level your driving the car. There are plenty of tracks where track day with stock seat and safety systems are adequate.

If you are an aggressive driver with history of driving your car off the track at track days I'd say yes invest in full blown crazy cage, proper seats, crash nets, full fire system, full fire suit, Hans etc. there are perfectly reasonable stages in between that are calculated risks.

To compare race car being driven at limits on very dangerous track can't be compared to track day driver driving well below limits on a safer track. Yes things can happen but likelihood is much less.

However if you're doing full on track car NASCAR door bars are excellent safety feature. Having top notch fabricator/welder is even more important then simple design elements. You could have what looks like a safe cage but if welder is inexperienced you could be in for rude surprise.