[UniverseHacker]

I agree, it's surprising. Even in California of all places, you can make a one-off vehicle at home and register it for legal road use, without even needing modern safety or emissions equipment:

https://www.jalopyjournal.com/forum/threads/registering-as-a...

Another even more common strategy is to "restore" a classic car using some extremely small number of parts from some really old pre-emissions and pre-safety equipment car. This is often done for hod rods, dune buggies, etc. where it will be, say a "1930 Ford" but contain only some minuscule amount of that original car it is titled and registered as. There's a sizable industry of homemade "kit cars" that require you to start with a legally registered VW Beetle, but ultimately they often retain nothing except parts of the thin sheet metal floor pan, and somehow that is apparently legal.