Cal. RTC § 8708

The board or its authorized representative may issue a California fuel trip permit to interstate users for entry into this state. The California fuel trip permit shall be valid for four consecutive days and includes any reentry into the state during the four-day period. The fee for issuance of a California fuel trip permit is thirty dollars ($30). Other provisions of this article and Article 1 (commencing with Section 8751) of Chapter 4 do not apply to the holder of a California fuel trip permit who uses only fuel brought into this state in the fuel tank of a qualified motor vehicle and fuel purchased from, and delivered into the fuel tank of the qualified motor vehicle by, a vendor. Any use fuel tax paid to a vendor for fuel taken out of the state in the fuel tank of a qualified motor vehicle operated under a California fuel trip permit shall not be refunded to the holder of the permit, notwithstanding any other provisions of this part.

The board may enter into an interagency agreement with the Department of Motor Vehicles providing for the issuance of California fuel trip permits by that department.