I used to live in california. I was actrully born and raised there. You can get ticketed if you have your car in the state of California for longer than 10 days without it being registered in california. And this means IF you ARE or ARE NOT a resident of california. They do not care. My advice don't register, if you get pulled over tell them youve been in the state since like yesterday and you plan on leaving at the beginning of the weekend. Honistly its hard to prove you have been there for 10 days. You could live in AZ or NV and just cross it frequently. once that car leaves cali the count would technically start all over. Heck I have my bike registered in a different state. Anytime im pulled over I go i didnt know I just got here and im leaving tomarrow. And most of the time there like. hum.
hes been here 3 days leaving tomarrow, well why waste the time on a stupid ticket? and if i wanna be lagit i just go over the boarder and come back.
But reality anything 10 days resident or not. Plus it has to pass smog and california safety checks. I hear its upwords of 400-600 to register an out of state car in the state. Goodluck to you and hope this post is very useful.