These have an upper and lower half and sandwich the stock rear subframe bushings. Since they are inserts they insert into the voids in the stock bushings filling them, and the gaps above and below the stock bushings with a stiffer urethane.

This better controls the movement of the rear subframe, tightening the back of the car, providing better throttle response and feedback, while also control dynamic alignment changes due to movement in the bushings.

Part Number KDT902 supercedes W0598