California Code, Vehicle Code - VEH § 6701

(a) Any nonresident owner of a vehicle registered in a foreign state who is a member or spouse of a member of the armed forces of the United States on active duty within this state, and any resident owner of a vehicle registered in a foreign state who is a member or spouse of a member of the armed forces of the United States returning from active duty in a foreign state, may operate the vehicle in this state without securing California registration after satisfying all of the following requirements:

(b) For purposes of paragraph (3) of subdivision (a), military orders do not include military orders for leave, for temporary duty, or for any other assignment of any nature requiring the military person's presence outside the foreign jurisdiction where the owner was regularly assigned and stationed for duty.

(c) This section applies to all vehicles owned by the military person or spouse except any commercial vehicle used in any business manner wherein the military person or spouse receives compensation.