Audi A4 / S4 / RS4 A4 / S4 / RS4 B8 (2008-2016) Rear Diff Front Bush Insert - PFR3-741 This is an insert to fit into the original bush to minimise the movement of the diff under acceleration. - NOTE: Price is for CAR KIT, NOT per bush… Powerflex price their bushes individually, but we have combined the quantities to make it simple!