In a case like that, do you have to install seat belts to drive it "legally"? I mean, it is legally registered here, without seat belts. At least I assume it is.
Seat belts are only required by law if the car came with them from the factory. They are not required for cars that did not originally come with them, and on my Impala, the original owner opted not to spend the money for the "seat belt option".
"Racing is life. Anything before or after is just waiting." - Steve McQueen