California Code, Vehicle Code - VEH § 27360

(a) Except as provided in Section 27363, a parent, legal guardian, or driver who transports a child under eight years of age on a highway in a motor vehicle, as defined in paragraph (1) of subdivision (c) of Section 27315, shall properly secure that child in a rear seat in an appropriate child passenger restraint system meeting applicable federal motor vehicle safety standards.

(b) Except as provided in Section 27363, a parent, legal guardian, or driver who transports a child under two years of age on a highway in a motor vehicle, as defined in paragraph (1) of subdivision (c) of Section 27315, shall properly secure the child in a rear-facing child passenger restraint system that meets applicable federal motor vehicle safety standards, unless the child weighs 40 or more pounds or is 40 or more inches tall. The child shall be secured in a manner that complies with the height and weight limits specified by the manufacturer of the child passenger restraint system.

(c) This section does not apply to a driver if the parent or legal guardian of the child is a passenger in the motor vehicle.

(d) This section shall become operative January 1, 2017.