Todd,
Dont know the reasoning, I think Cobras look great without screens.
Regs just say all cars must have Windscreen except for open class where you can run race tyres and any engine mod and aero screen if you wish.
Also this year Wakefield management have stated that roll bars must be fitted to all open cars. If you want an instructor on board then dual or one big single roll bar will be required.
Phil.
