Regular glass is fine for road race but in modern times banned for oval track due to taking longer to clean the track up. I looked at the main rule set and " How not to fail tech " rule set as well, it says nothing about windshield clips. ( see bottom for links ) Yes, most other road race sanctioning bodies specify clips and sometimes 3 bars in the center to prevent a tire from entering the car.

The glass appears to be OE because I don't see any fine scratches one gets with Lexan. ( curved glass makes the car a Super Bug )

Here is a reason why glass / screen is mandated. https://www.youtube.com/watch?v=NwPfjXgh3ng ( Use the " gear " menu to slow the speed down, start looking at 0:05 , it didn't go through. ) Link to still pic > https://www.caranddriver.com/news/video-lemons-peugeot-mi16-throws-rod-into-trailing-celicas-windshield

https://24hoursoflemons.com/prices-rules/

https://24hoursoflemons.com/wp-content/uploads/2017/06/How-To-Not-Fail-Lemons-Tech_v3_051817.pdf