KingBear
Hooligan
Oh yeah, we have the motor vehicle gestapo in pretty much every state. It is designed to ensure the emission compliance and safety of the vehicles on the road, and to raise state funds, but I'm not sure which would be considered the primary and secondary purpose. Flagrant violations can also be written up by police officers at any time as a "fix-it ticket", where you would have to present your vehicle and show you've brought it into compliance. Many older vehicles are either exempt or have lighter restrictions.
Good luck!