BMW 4 Series G22, G23, G82, G83 (2020 on) Rear Diff Front Mounting Bush - PFR5-4024BLK PFR5-4024 Rear Diff Front Mounting Bush is a new part number full bush replacement, reconfigured from existing CNC Aluminium componentry and polyurethane bushes. Made combining our signature Black 95A durometer polyurethane and Black anodised 2011-T6 aluminium, to reduce drivetrain deflection and the potential for wheel-hop during hard launches. - NOTE: Price is for CAR KIT, NOT per bush… Powerflex price their bushes individually, but we have combined the quantities to make it simple!