TMS solid sub-frame bushings are designed around current SCCA SPEED World Challenge regulations, and developed by the TMS WC race team. A BMWs subframe is the heart of the suspension. When the subframe moves, so do all the suspension mounting points. Replace the stock rubber bushings to limit drivetrain and suspension movement and keep your car setup the way its supposed to be. Solid bushings will also help keep the subframe from tearing out of the chassis. One front bushing is slotted to allow for compliance between manufacturing standards as BMW specifies. These bushings are CNC machined out of high grade billet aluminum.