My definition,
If it has wheels and can be driven without you getting arrested, or endangering others lives its a street car. If your cars exhaust can make people in the other lane light headed from the fumes..... not a street car. If your car is so loud that people around you cant hear emergency vehicles... not a street car
Not all cars can driven in snow, not all cars have air bags, not all cars have extra seats, not all cars have 5 star crash ratings. You dont have to have ac, a radio, or any comfort feature. A cars primary purpose is to get you from point a to point b. Even if your car stalls at every light, as long as it starts back up when the light is green its still a street car. We dont have the emissions testion like other cities so I wouldnt include cats.