California Code, Revenue and Taxation Code - RTC § 9012.6

Notice of the sale shall be given in writing to the delinquent user and to all persons appearing of record to have an interest in the motor vehicle at least 10 days before the date set for the sale of the vehicle.  The notice shall be enclosed in an envelope addressed to the user at his last known residence or place of business and, in the case of any person appearing of record to have an interest in the motor vehicle, addressed to the person at his last known residence or place of business.  It shall be deposited in the United States mail, postage prepaid.  The notice shall contain a description of the motor vehicle to be sold, a statement of the amount due, interest, penalties and costs, the name of the user, and the further statement that unless the tax due, interest, penalties and costs are paid within 10 days the motor vehicle will be sold at private sale.