The National Highway Traffic Safety Administration (NHTSA), the federal agency responsible for reducing accidents, deaths, and injuries resulting from motor vehicle crashes on the nation's highways, estimates that over 6 million automobile accidents occurred in the United States in 1999. To repair crash-damaged vehicles, consumers spent over $8 billion and bought over 61 million sheet metal and plastic body parts (including exterior fenders, bumpers, hoods, and doors). Consumers and body shops that repair crash-damaged vehicles have a choice in many instances of buying new replacement parts from either the original equipment manufacturer or other sources, commonly called after market manufacturers. These after market manufacturers produce their parts by copying the design of the original vehicle parts.