Cal. Health & Safety Code § 11366.8

(a) Every person who possesses, uses, or controls a false compartment with the intent to store, conceal, smuggle, or transport a controlled substance within the false compartment shall be punished by imprisonment in a county jail for a term of imprisonment not to exceed one year or pursuant to subdivision (h) of Section 1170 of the Penal Code.
(b) Every person who designs, constructs, builds, alters, or fabricates a false compartment for, or installs or attaches a false compartment to, a vehicle with the intent to store, conceal, smuggle, or transport a controlled substance shall be punished by imprisonment pursuant to subdivision (h) of Section 1170 of the Penal Code for 16 months or two or three years.
(c) The term “vehicle” means any of the following vehicles without regard to whether the vehicles are private or commercial, including, but not limited to, cars, trucks, buses, aircraft, boats, ships, yachts, and vessels.
(d) The term “false compartment” means any box, container, space, or enclosure that is intended for use or designed for use to conceal, hide, or otherwise prevent discovery of any controlled substance within or attached to a vehicle, including, but not limited to, any of the following:
1. (1) False, altered, or modified fuel tanks.
2. (2) Original factory equipment of a vehicle that is modified, altered, or changed.
3. (3) Compartment, space, or box that is added to, or fabricated, made, or created from, existing compartments, spaces, or boxes within a vehicle.