BMW 3 Series F30, F31, F34, F80 (2011 - 2018) Rear Diff Front Mounting Bush - PFR5-4025 PFR5-4025 is a replacement bush that includes aluminium sleeves with built-in support to increase control of rear diff movement and replaces all four bushes in the original rear diff front mounting bracket. - NOTE: Price is for CAR KIT, NOT per bush… Powerflex price their bushes individually, but we have combined the quantities to make it simple!