Seizing a vehicle is a disproportionate response to the minor social harm (if any) caused by drivers who use their cars and trucks to solicit a prostitute or to buy small quantities of marijuana. The California Supreme Court, by a 4-3 vote, struck down city ordinances that purport to authorize the seizure and forfeiture of vehicles used to commit those crimes on the ground that state law does not authorize cities to impose that penalty.

The Court invalidated a Stockton ordinance that authorized the police to seize a vehicle if they have probable cause to believe it was used to solicit an act of prostitution or to acquire any controlled substance. The ordinance provided that title to the vehicle would vest in the City, and gave the City a generous year to hang onto the vehicle before starting a forfeiture proceeding. Because the Court found that the ordinance was preempted by the state criminal code, it didn't reach the obvious due process concerns that the ordinance raised.

The decision is here (pdf).