[Demo Derby Masters - Keyser Manufacturing Demo Derby Masters is the premier destination for demolition derby drivers and car builders. We offer a wide array of stock demolition derby parts and accessories. We also provide custom fabrication and design services to turn your ideas into reality. Our team of engineers and demo derby drivers have designed, manufactured and “derby tested” all parts to insure quality and durability, even under the most extreme conditions. Our parts are manufactured, housed, and shipped out of our 140,000 square foot facility located in Coopersville, Michigan.]