Yep, out of state registration is good. The way the law is written, is if you are "living" in the state of California longer than 90 days, you need to register your vehicle here. There is even another loophole around that. You can purchase a California Non-resident OHV sticker from several retailers around San Diego. One I know of for sure that always has them in stock is Off Road Warehouse. There are 3 in San Diego. One in Escondido, Clairemont Mesa, and El Cajon. I don't remember how much it is, but I think it's like $25-$30 and will make you 100% legit. It's worth paying for to avoid any future headaches, in my opinion.