This was also a few years back, Danny Thompson in a newer Mustang. This video shows a couple things that I think are important.
Look how much he moves around when they show the slow motion. I know from experience that before a run the starter comes over and tightens the belts. I thought mine were tight enough, the starter made them tighter.
The other thing, imagine this without some sort of head/neck restraint...your frickin head would fall off!
https://m.youtube.com/watch?v=TTzbBRyOO0o