Mustang C&R third member (Detroit Locker) modified by Mike Maier Inc | MMI. Ultimate performance for your early model pony car. C&R Racing has provided NASCAR with their third members for years. We have taken C&R’s equipment and put the MMi touches on the part. We have tuned the locker to work in both street and race applications. Detroit lockers are the best in putting the power to the ground for your vintage Mustang.