What's a Rust Belt state doing in the Top 5? Answer: a disproportionately high concentration of fast cars. As Illinois' biggest city, Chicago represents the pioneering Midwestern hot rodding culture in an extreme kind of way. In this neck of the woods, everyone emerges from their garages after working on their cars all winter with a new combination of parts aching for a beat down. Combine this structured hot rodding schedule with the population of the third-largest city in the country, and you get a ton of fast cars. Although there's no practical way to accurately gauge this sort of thing, Chicago has what's arguably the highest concentration of 9- and 8-second street cars in the country. And whether they're muscle cars or street rods, they're all nice. As the locals explain, all the jalopies rusted out a long time ago, so all that's left is the good stuff. Surely, a state so conducive to speed must be friendly to the hobby, and the facts reinforce this assessment. The state enacted SEMA's model legislation for titling and registering muscle cars and street rods back in 2002. Although the areas surrounding Chicago and East St. Louis do enforce smog tests, pre-'68 vehicles are exempt, as are muscle cars that are 25 years and older, which fall into Illinois' antique vehicle category. Smog laws are even lenient enough to make exemptions for race cars. So if you have a late-model car that's only driven at the track, just fill out an affidavit and your ride is smog exempt. Like neighboring Kentucky, Illinois has over three-dozen dirt and paved oval tracks in addition to a half-dozen dragstrips. No wonder this place is home to so many fast cars.