Easy the best racing rivalry of all time. Achille Varzi vs Tazio Nuvolari. Look it up.
Considering his fame through computer games it could be possible to get a Colin McRae story off the ground. Film would have to include his rivalry to Richard Burns and both of their tragic passings. RIP
I read that book (The Limit) early this year and enjoyed it very much. I think it could make a fantastic movie. Given that the story spans something like 10 years, and that there aren't very many 50s and early 60s F1 and sports racing cars lying around, I think it would be very expensive to produce unless it were done with a lot of CGI.