Lexan Windshield

quoted exactly from NHRA rule book

7.10 WINDSHIELD, WINDOWS, Stock-bodied vehicles

Mandatory, must be in good condition and free from cracks. May be replaced with shatterproof material, 1/8-inch (3.2 mm) minimum thickness. Windshield may not be cut for scoops, carb, etc. Windshield/window tint must meet the applicable government requirements. Windows must be closed during races, need not be operable. Decals permitted on rear quarter and rear window only.