I can’t speak from experience on this, but it appears that if you want to roll your car, the best way is to go off track, sideways if possible. If the track is inherently unsafe, for example, with dirt banks, you may find yourself on your roof just from leaving the racing surface.
Another way is to hit a barrier.
If you go off sideways, you can roll just from landscape braking.
Continuing the Taxonomy of Suckage…
It’s said that a bad craftsman blames his tools. But sometimes the tools really do suck. An Evil Handling Vehicle (EHV) can be a real hazard on the race track. My own experience with an EHV occurred when our 1986 MR2 broke a spindle and we hastily repaired some of the suspension components with parts from a 1984 MR2 (which aren’t the same size). You had to fight the wheel to keep the car going straight and left turns saw the car leaping off line. It was like riding a wild animal. I can recall going 3 wide through the carousel at Sonoma with the car trying to kill me every step of the way… un-freaking-forgetable (oddly, in a good way).
Check out this clip of an EHV that is so bad it rolls over under a yellow flag. Damnit, I’d love to drive that POS.