I think a roll bar was required last year but it doesn't look like it is for this year. A funny story.. Several years ago my friends said "come out, bring your Bronco and compete, you'll have a blast". Well, I showed up just before the start on opening morning, they rushed me through tech, gave a number, had the drivers meeting, and then I turned around really got to see the course for the first time. "Holy Sh**, what am I doing?", I thought to myself. So I went on to have a blast. I've had a few close calls on the course since then, put a few dents and dings in my rig out there too. But I've had a blast out there and will be back this year too. Street/Stock is a fun class to be in, the whole event is a blast.
Do expect to find any weak link in your rig.
-Steve