This wasn't in a "class" car, but it was at the 1980 NHRA World Finals in Ontario, CA involving (I'm pretty sure) Jerry Valentine.
After bracket racing all year in Florida, winning the track championship at Orlando Speed World and then the Division 2 championship in Pro ET at Gainesville, I got to go to NHRA's first world championship race for NHRA bracket cars. Once in tech, I was shocked to learn that my 3 or 4 point roll bar wasn't legal because I didn't have a side bar!

(East coast/West coast rules?

) I may have been missing the support plates under the floor as well. So here I was on the opposite side of the country, late in the afternoon and unable to race at the biggest event I've ever been to. Luckily an old friend who now lived in San Diego was helping me out and he found a muffler shop that was open. Got some plates welded/bolted in underneath along with
exhaust tubing as a side bar, nicely painted and padded. I was nervous, but obviously had nothing to lose. Somehow, surprisingly, Mr. Valentine passed me early the next morning and I made first round. I was exhausted, nervous and redlighted very badly. I had a shot, but I can't help but wonder what may have been if I had gotten a good night's rest. I believe it was a 3 or 4 round race because not all of the qualifying division champions made it.

At least I was there and it's a memory I'll never forget.