Mercedes-Benz CLA Class W117 & W156 (2012-2016) Upper Engine Mount Insert - PFF40-120 This is an insert to fit into the original mount to limit movement of the engine to provide stability under acceleration. A small increase in noise and vibration is to be expected. This should be considered as a performance upgrade. - NOTE: Price is for CAR KIT, NOT per bush… Powerflex price their bushes individually, but we have combined the quantities to make it simple!