I think we should *encourage* Commufornia to enact *ridiculously* restrictive motor vehicle laws. Then the automakers will have to build one type of vehicle to sell in Commufornia, and another to sell on Earth.
The Commufornians will then have to bear the expense of their own stupidity, and the rest of us can have cheap automobiles. But it will only work if Commufornia enacts *really* strict restrictions - a small, incremental difference will only cause the automakers to build the more restrictive model and pass the expense on to the humans as well as the Commufornians.
For years, major automakers have sold California versions of their products which are outfitted with special emissions control equpment. And sold a 49-state version in the rest of the USA. This is nothing new.