If you declare California as your permanent residence, your car must be registered with the DMV within 20 days of arriving here. Your car must be smog checked before you can register it. Take your smog certification, out-of-state registration, title, and checkbook to a DMV office. Your car will also have to be present so that a DMV officer can verify the VIN. More information about vehicle registration and smog checks (including smog testing centers) can be found at www.dmv.ca.gov/vr/vr.htm.