If you are a current member of NIADA, Used Car Dealer Magazine (UCD) is one of your many membership benefits and therefore you will receive a monthly issue of the leading magazine of the used car industry. Used Car Dealer magazine is the official publication of the National Independent Automobile Dealers Association (NIADA). While newcomers strive to gain a foothold, Used Car Dealer has remained the premier publication for used motor vehicle industry and motor vehicle executives in the United States. Get the latest news, strategy, information and industry insights in your mailbox each month. Order Used Car Dealer Magazine.