Quote:

I believe the Optima rules say a rollbar is mandatory.



http://www.optimabatteries.com/en-us/experience/optima-invitational/rules/official-ousci-rules/

Only thing I found on the website was that they are mandatory on convertibles and allowed on other cars. If your car is fast enough to be competitive for this event you probably should have a cage...

Sounds like the national challenge event is by invitation only, car must have been displayed at SEMA and you have to be a member of their insider club and display their advertising on your car.

-Michael

Michael 1968 Barracuda Notchback Coupe 440 EFI 6-pack, T56 Magnum 6-spd