All you need to be a street car is an engine that runs, not be so loud that when you pass people they grab their bleeding ears and crash, and put tires on it that can drive in an unexpected rain shower safely.
Nevermind... looking at some of the hoopties on the road all you need is an engine. You dont need rear view mirrors, tread on your tires, an exhaust... Hell I have seen cars with fold out chairs in them