Matthew Fox told Entertainment Weekly that, while he didn't know anything about Speed Racer (he grew up without a TV!), he's a big cartoon, comic book and anime fan.
"So when I found out that the
Wachowski's were doing '
Speed Racer' and were interested in me for it, I immediately went on the Internet, and as soon as I saw
Racer X, I was like, I think that looks like me. I kinda think I would be a good
Racer X. [Laughs] So then I was like, Dammit, I'm going to win this role! I went and read for it, and then waited quite a while."
Fox added that "
Racer X is all about mystery. And it's all about not just disguise of suit, but it's disguise of voice — he's, like, impenetrable." (
source)