Those guys have large ones. No, make that HUGE ones.
I attended a small dinner put on by Toyota last year with a group including Juan Fangio II, Ivan Stuart and Rod Millen. Rod seemed pretty unasuming considering he must have more guts than most men alive. I could not even imagine driving those roads at that speeds. He acted like it wasn't that big of a deal.
Juan Fangio II looked like he belonged in an Elvis Presley moving portraying a rich playboy and he had his very good looking young "niece" with him.
Ivan must spend a great deal of his time in the gym. The guy is ripped for his age.