Established in 1981, Grand Traverse Plastics Corporation is a privately held custom injection molding company that specializes in error proofed manufacturing processes yielding superior quality performance. The company s full-service engineering and research and development capabilities allow it to manage a program from quotation to production. It supports simultaneous engineering, value analysis and value engineering, and provides local support for all program management activity. Products include decorated and functional engine covers, under hood and underbody powertrain parts, wiring channels, interior trim, close tolerance molding, riveting, insert molding, sonic welding, overmolding, exterior mirror housings and a variety of sporting goods. Grand Traverse Plastics Corporation is located in Williamsburg, Mich.