I have heard lawyers advance the view that confiscating vehicles before someone is convicted would violate the Constitution. The proof is going to be someone who has a vehicle confiscated and have the case go before the California Supreme Court, and possible the SCOTUS. There could be some sort of civil abatement reasoning, in that the customers and their vehicles contribute to a public nuisance, and that they only need a preponderance of evidence (50%) to prove in civil court that the vehicle should therefore be confiscated.
I would like to see proof that picking on prostitutes and their customers somehow makes the community safer. There is an enormous amount of death and disease being spread by gays. No one has the balls to try and stop them though. These operations are oppressive, cowardly, and are simply a different form of taxation, and they stink.