Sneaking in without a roll cage

Depends on the track and how well or if they actually do tech. A roll bar is required at 11.49 1/4 mile, a roll cage isn't required until 10.99 or 9.99 if your floor and such isn't all cut up. I wouldn't run a car without proper safety equipment, but most tracks if it's your first time there and they don't know your car you can usually get 1 full pass and if it's too fast they will tell you to go home. You could always lift at the 1/8th mile on the 1st run to see how fast you maybe, or even if you're as fast as you think you should be. I've seen a few "600" HP cars not need a roll bar.