This 3pc. CNC aluminum gold anodized bushing set replaces the two rear cover and single OEM subframe diff mounts on the E46 M3. When taking care of the getting the power to the ground at the diff mounts, its also a great time to reinforce the chassis and install solid subframe bushings which are both sold separately. We sell a different Non-M set as well for all other 3 series. Check the gallery for install images. ~Solid diff bushings will increase rotational drivetrain noise, but will eliminate clunking and noise from worn rubber bushings.