Manufacturers absolutely do make only-for-sale-in-California-variant cars. Motorcycles, also. They're not as common as they used to be because emissions laws elsewhere are also starting to become as stringent as the CARB rules these days as well, so it's becoming more cost effective to just make everything the "California version."

Throughout the early 2000's, the distinction was much more relevant. The last vehicle I had to work on that I know for a fact to be a "California version" was a 2014 KLR650. It has additional (unreliable...) emissions control equipment that is not present on otherwise identical bikes from the same model year that were not intended for sale in California.

Furthermore, California will refuse to plate any vehicle that does not specifically have a California compliant emissions certification if it has fewer than 7500 miles on it, i.e. if it is new. Those that don't meet California's standards are labeled "49 state" vehicles.