California DMV Law
There is a body of law which governs the handling of California Department of Motor Vehicles cases stemming from a driving under the influence arrest. This body of law includes statutes and interpretive court decisions from California appellate courts. This area of California law is not generally relevant to lawyers who don't specialize in California DUI defense.
For that reason, if you have been arrested for a DUI in San Francisco, you should seriously consider hiring an attorney who specializes in California DUI law and is based in San Francisco in order to ensure familiarity with the procedures and practices of the San Francisco Superior Court.