Polyurethane Bushing Kit, Sway Bar End Links, XJ-6 and XJ-12 Series I, II and III; XJ-S. Car set of eight polyurethane versions of factory number C10996. Black. Our polyurethane suspension bushings offer a number of advantages over standard rubber bushings: They will last the life of the car and offer unequaled resistance to dry rot and ozone. They also offer a seemingly impossible combination of better performance through less deflection but with virtually no penalty in ride quality. Finally, they do not squeak! WeÕve sold thousands of polyurethane suspension bushings over the years and use them extensively in our restoration and service shop.