Cal. Government Code § 53075.61

A transportation inspector, authorized by a local government to cite any person for operating as a taxicab without a valid taxicab certificate, license, or permit required by any ordinance, may impound and retain possession of any vehicle used in a violation of the ordinance. If the vehicle is seized from a person who is not the owner of the vehicle, the impounding authority shall immediately give notice to the owner by first-class mail. The vehicle shall immediately be returned to the owner without cost to the owner if the infraction or violation is not prosecuted or is dismissed, the owner is found not guilty of the offense, or it is determined that the vehicle was used in violation of the ordinance without the knowledge and consent of the owner. Otherwise, the vehicle shall be returned to the owner upon payment of any fine ordered by the court. After the expiration of six weeks from the final disposition of the criminal case, the impounding authority may deal with the vehicle as lost or abandoned property under Section 1411 of the Penal Code. At any time, a person may make a motion in superior court for the immediate return of a vehicle on the ground that there was no probable cause to seize it or that there is some other good cause, as determined by the court, for the return of the vehicle. A proceeding under this paragraph is a limited civil case. No officer or employee, however, shall impound any vehicle owned or operated by a nonprofit organization exempt from taxation pursuant to Section 501(c)(3) of the Internal Revenue Code which serves youth or senior citizens and provides transportation incidental to its programs or services.