Headquartered in Westlake Village, Calif., J.D. Power and Associates is a global marketing information services company operating in key business sectors including market research, forecasting, performance improvement, Web intelligence and customer satisfaction. The company's quality and satisfaction measurements are based on responses from millions of consumers annually. For more information on car reviews and ratings, car insurance, health insurance, cell phone ratings, and more, please visit JDPower.com. J.D. Power and Associates is a business unit of The McGraw-Hill Companies.