Au-Tomotive Gold, Inc. (Auto Gold) (plaintiff) manufactured automobile accessories, like license-plate covers and key chains. Auto Gold put exact replicas of the marks used by famous automobile makers, like Mercedes and BMW, on Auto Gold’s products. Auto Gold had licensing agreements with some, but not all, of the automobile manufacturers whose marks Auto Gold used on its products. For example, Auto Gold sold products bearing the marks of Volkswagen of America, Inc. (Volkswagen) and Audi (defendants) without their permission. Auto Gold sued Volkswagen and Audi seeking a declaratory judgment that, among other things, Auto Gold’s products did not infringe on Volkswagen’s and Audi’s trademarks. Auto Gold argued that, under the doctrine of aesthetic functionality, Volkswagen’s and Audi’s marks were not eligible for trademark protection. Auto Gold moved for summary judgment on the issue of trademark infringement. The district court granted Auto Gold’s motion, issued a declaratory judgment that Auto Gold’s products did not infringe the Volkswagen’s and Audi’s trademarks, and enjoined Volkswagen and Audi from enforcing their trademarks against Auto Gold. Volkswagen and Audi appealed.