Someone could compile every vehicle regulation from all the states into one common list. It'd be more restrictive than any single state, but it would be consistent. And if someone doesn't like it, they can fall back to their local laws.

this pretty much exists. thats where the malformed plate info generated by Fluck gets input and results in drivers of partial match plates 4 to 6 states from the away getting pulled out of cars at gunpoint. registration is just a different dataset in the same system. 20+ years ago most PD dispatches had a terminal dedicated to out of state registration lookups... today its in the patrol car.

I think people have a valid point complaining about california writing the laws for the rest of the nation.