It's a documentary about Irish racing driver Tommy Byrne, a.k.a. "The best racing driver you haven't seen". He was very fast - and he clearly possessed enough natural talent to make it in Formula One. Problem was, he was a 'daredevil' character, and by the time he arrived on the scene (in the early 1980s), Formula One was moving away from that, and becoming increasingly corporate and professional. Everyone recognised and respected his ability, but he just didn't fit in with the culture any more. So, he went to America, and won a bunch of races there .
I'd give it a thumbs-up. It taught me quite a lot that I didn't know!