Factory rear trailing arm bushings allow for two undesirable scenarios: premature failure and unexpected changes in toe. Limiting side-to-side deflection of the rear trailing arm, limiters surround the rear trailing arm bushing, maximizing bushing life while eliminating undesired rear toe changes. This alignment retention allows for more predictable handling in corners and over bumps, without a loss of ride quality. Manufactured in the USA of wear resistant, noise resistant delrin, ECS RTAB limiters offer a simple solution to an inferior factory design. Simple to install during a rear trailing arm bushing service, these limiters are a must for all E36/E46 3 Series and E85/E86 Z4 models, regardless if they are street or track driven. Sold as a set of four, one set required per vehicle. *Not to be used with poly bushings.