They will probably ban that conduct next year. They already made it more or less illegal to bring in a car from out of state to get around their ever more asinine vehicle control regulations.
Ditto for motorcycles. I carted my 2009 Suzuki DR650SE with me to San Diego. I was purchased in August 2008. It arrived with 880 miles on the odometer. After riding around after work and trying a commute 35 miles one way on the freeway, I deemed it unsatisfactory for a daily commuter. I had 1300 miles on the odometer and wanted to trade it in on a 2009 Kawasaki Versys. No way. It can't be registered or sold until it has 7500+ miles on the odometer if purchased out of state. The dealer arranged to cart the bike out of state to an auction and I got $3500 for a bike that had cost me about $5800 at that point in the game. The Versys is doing what I need as a commuter, but I took a terrible bath due to asinine CA laws.
In retrospect, I could have just kept the DR650SE and purchased a used VStar 650 for about $3900 on Craig's list. It would have been perfectly satisfactory.