The California Supreme Court has ruled in Sanchez v. Valencia Holding Co. LLC, which centered over the enforceability of an arbitration provision in a car dealer's sales contract. The court has reversed the lower court's decision and followed AT&T Mobility v. Conception, a U.S. Supreme Court decision which held that the Federal Arbitration Act of 1925 preempts state laws that prohibit contracts from disallowing class action waivers. 

Read the Sanchez v. Valencia Holding Company ruling.