N.A.D.A. Appraisal Guides publishes used vehicle value guides for individuals and businesses that are buying, selling or trading automobiles, classic cars, motorcycles, boats, recreational vehicles and manufactured homes. Its customers include consumers, government agencies, insurance companies, banks, credit unions, financial institutions and fleet and lease companies. The company produces more than 600,000 guides every month and more than 7 million per year. N.A.D.A. values are derived from research compiled from a variety of sources, including trade shows, manufacturer previews, auctions, new and used dealers, auto shows, trade periodicals, vehicle classifieds, magazines, newspapers, advisory boards, associations and car clubs. The company also classifies vehicles into categories based upon the vehicle's condition - low, average and high. N.A.D.A is headquartered in Costa Mesa, Calif.