Condor Speed Shop - Rear 12mm Subframe Riser Bushings - E30Solid Rear 12mm Subframe Riser Bushings are designed to extend the life of your rear tires. When you lower an E30, you will begin to wear out the insides of your rear tires due to excessive rear camber. The lower you go the bigger the problem. These solid bushings are designed to raise the rear subframe 12 millimeters to correct extreme negative camber on lowered cars. UHMW is comparable to solid aluminum mounts in stiffness, but to poly mounts in