Powerflex BMW M2/M3/M4 Dual Mount Rear Differential Bracket (F80/F82/F83/F87)Powerflex BMW M3 M4 Dual Mount Rear Differential Bracket replaces BMW's factory single bush bracket that promotes excessive wear on the rear subframe to diff bush. This design is very flawed as is creates a pivot point for the diff under torque loading. With hard launch starts and sudden and frequent on off throttle changes, this puts the single rear OE rubber bush through extreme torsional and directional forces, resulting in accelerated ageing with