[potato3732842]

You're projecting California onto the entire country. Many states thad mandate 50-state compliance for new sales stop caring after and most of them only do a plug in test anyway. Many states don't test at all.

Vehicle mods exist in the same sort of patchwork of "illegal to various degrees but nobody cares" gray areas that weed does.

At the end of the day enforcement is capped by political will.