California Code, Revenue and Taxation Code - RTC § 8401

(a) Obtain motor vehicle fuel for export and fail to export it, or cause it not to be exported.

(b) Divert motor vehicle fuel, or cause it to be diverted, from interstate or foreign transit begun in this state.

(c) Return motor vehicle fuel to this state and sell or use it, or cause it to be used or sold in this state, without complying with the provisions of this part and without notifying the supplier from whom the motor vehicle fuel was originally purchased of his or her act.

It is unlawful for any supplier or other person to conspire with any person, firm, association, or corporation, or any officer or agent thereof, to withhold motor vehicle fuel from export, or to divert it from interstate or foreign transit begun in this state, or to return it to this state for sale or use so as to avoid any of the taxes imposed by this part.

Any person violating any provision of this section is guilty of a misdemeanor punishable as provided in Section 8402.

Each shipment illegally diverted or illegally returned constitutes a separate offense, and the unit of each shipment is the cargo of one vessel, or one railroad carload, or one automobile truck load, or such truck and trailer load, or one drum, or one barrel, or one case, or one can.