If you are coming out to sunny So. Cal. with the military, then you can be excused from having to register your car in the State. If you are simply moving out here as Jeepguy Q. Public, then you are required to register the car within ten days of moving. It used to be 20 days, but the State found they could reap many more dollars in back fees.
That is how the law is written. Take a little time, get settled, but don't take too long. Just remember you moved here 10 days ago. A caveat - if the local constabulary should happen to drive by your abode, and note out-of-State tags, for an extended period, you could receive a summons to the DMV complete with fines already listed.
Fortunately they recently declared the environmental impact fee unconstitutional. That used to bump the registration $300.00 above and beyond the normal registration costs.
Let us know when you get here, well on second thought, um, let me know sometime after you have your tags
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.