I wrote:
No doubt this is true. For that matter there are regional variations in cars such as the type of fuel allowed (more or less polluting) and customer requirements for things like road salt sealants . . .
What I am trying to say is that manufacturers can support small regional variations, but they cannot manufacture radically different vehicles for California versus the rest of the country. To take an extreme example that isn't going to happen: suppose California were to mandate that half the cars sold in 5 years must be plug in hybrids. The manufacturers would have to spend billions gearing up to meet this mandate. They would then go ahead and sell the plug in hybrids in other states as well. They would have to, in order to survive.
- Jed
