Cal. Vehicle Code § 4751

The department may refuse registration or the renewal or transfer of registration of a vehicle in any of the following events: (a) If the department is not satisfied that the applicant is entitled thereto under this code. (b) If the applicant has failed to furnish the department with information required in the application or reasonable additional information required by the department. (c) If the department determines that the applicant has made or permitted unlawful use of any registration certificate, certificate of ownership, or license plates. (d) If the vehicle is mechanically unfit or unsafe to be operated or moved on the highways. (e) If the department determines that a manufacturer or dealer has failed during the current or previous year to comply with the provisions of this code relating to the giving of notice to the department of the transfer of a vehicle during the current or previous year. (f) If the department determines that a lien exists, pursuant to Section 9800, against one or more other vehicles in which the applicant has an ownership interest. (g) If the applicant has failed to furnish the department with an odometer disclosure statement pursuant to subsection (a) of Section 32705 of Title 49 of the United States Code.