California Code, Vehicle Code - VEH § 23594

(a) Except as provided in subdivision (b), the interest of any registered owner of a motor vehicle that has been used in the commission of a violation of Section 23152 or 23153 for which the owner was convicted, is subject to impoundment as provided in this section. Upon conviction, the court may order the vehicle impounded at the registered owner's expense for not less than one nor more than 30 days.

If the offense occurred within five years of a prior offense which resulted in conviction of a violation of Section 23152 or 23153, the prior conviction shall also be charged in the accusatory pleading and if admitted or found to be true by the jury upon a jury trial or by the court upon a court trial, the court shall, except in an unusual case where the interests of justice would best be served by not ordering impoundment, order the vehicle impounded at the registered owner's expense for not less than one nor more than 30 days.

If the offense occurred within five years of two or more prior offenses which resulted in convictions of violations of Section 23152 or 23153, the prior convictions shall also be charged in the accusatory pleading and if admitted or found to be true by the jury upon a jury trial or by the court upon a court trial, the court shall, except in an unusual case where the interests of justice would best be served by not ordering impoundment, order the vehicle impounded at the registered owner's expense for not less than one nor more than 90 days.

For the purposes of this section, the court may consider in the interests of justice factors such as whether impoundment of the vehicle would result in a loss of employment of the offender or the offender's family, impair the ability of the offender or the offender's family to attend school or obtain medical care, result in the loss of the vehicle because of inability to pay impoundment fees, or unfairly infringe upon community property rights or any other facts the court finds relevant. When no impoundment is ordered in an unusual case pursuant to this section, the court shall specify on the record and shall enter in the minutes the circumstances indicating that the interests of justice would best be served by that disposition.

(b) No vehicle which may be lawfully driven on the highway with a class C or class M driver's license, as specified in Section 12804.9, is subject to impoundment under this section if there is a community property interest in the vehicle owned by a person other than the defendant and the vehicle is the sole vehicle available to the defendant's immediate family which may be operated on the highway with a class C or class M driver's license.