I'm into pretty much anything with 4 wheels that goes fast lol. NASCAR, IndyCar, some drag racing, the occasional Formula 1.
But when it comes to NASCAR I'm not near as big into as I was 10 years ago. Used to never miss a lap of any race. Now there's only about 4 all season I'll watch start to finish.
I've for some reason never actually gotten TO a live race(major series) though. Only live 2 hours from Michigan, 3 from Indy, 4 from Chicago, 2 from Mid Ohio, probably about 4 from Kentucky, so there's plenty of tracks I could get to. Just never seem to be able to balance time and money to be able to go. Made it for practice and qualifying at Michigan one year though and that was a nice experience.
Edit: Pretty much everyone in my hometown, whether they admit it or not, is into racing in some form. Kind of hard not to be when your most famous resident is an Indy 500 winner and has made 110 starts at the Sprint Cup level.