From the California DMV web site:
Waiver of Penalties and Registration Fees
9562. (a) When a transferee or purchaser of a vehicle applies for transfer of registration, as provided in Section 5902, and it is determined by the department that registration penalties accrued prior to the purchase of the vehicle, and that the transferee or purchaser was not cognizant of the nonpayment of the fees for registration for the current or prior registration years, the department may waive the registration penalties upon payment of the fees for registration due.
(b) Other provisions of this code notwithstanding, the director may, at his or her discretion, investigate into the circumstances of any application for registration to ascertain if penalties had accrued through no fault or intent of the owner. If the director determines that the circumstances justify it, he or she may waive any penalties upon payment of the fees for registration then due.
(c) When a transferee or purchaser of a vehicle applies for transfer of registration of a vehicle, and it is determined by the department that fees for registration of the vehicle for any year are unpaid and due, that the fees became due prior to the transfer or purchase of the vehicle by the transferee or purchaser and that the transferee or purchaser was not cognizant of the fact that the fees were unpaid and due, the department may waive the fees and any penalty thereon if the license plate assigned to the vehicle displays a validating device issued by the department and the validating device contains the year number of the registration year for which the transferee or purchaser is requesting a waiver of fees and penalties.
(d) Upon the transfer of a vehicle for which fees for registration and any penalties thereon are unpaid and due, the fees and penalties are, notwithstanding the provisions of Article 6 (commencing with Section 9800) of this chapter, the personal debt of the transferor of the vehicle who did not pay the fees and penalties when they became due or accrued.
The fees and penalties may be collected by the department in an appropriate civil action if the department has waived the fees and penalties pursuant to subdivision (c).
Amended Ch. 223, Stats. 1993. Effective January 1, 1994.
Tom