AKG Motorsport Rear Trailing Arm Bushings, Poly 95A – E36, E46, Z4Product Description These BMW E36, E46, Z4 Polyurethane (95A) Rear Trailing Arm Bushings (RTAB) hold the rear trailing arms in place to help prevent geometry changes keeping alignment and handling consistent. In addition, our unique bushing design incorporates grease grooves for easy lubrication. The factory rubber rear trailing arm bushings are soft and wear out quickly, creating fluctuations in suspension geometry that adversely affects everything