street cars that see heavy track use, dedicated track cars:
Red urethane isolated transmission mount bushings, which are replacing our previous-style red neoprene. These are fully isolated, having two separate mounting bolt hardware pieces embedded in the material just like the black neoprene and OE BMW bushings. The urethane is a higher durometer (stiffer) material than the neoprene and offers nearly the same drivetrain motion control as a solid delrin or aluminum mount, but with significant vibration isolation. That last detail makes it a better choice for a track car that is occassionally street-driven, where cabin noise is a concern. While UUC does expect some vibration transmitted into the cabin, initial user reports say that it is minimal and certainly acceptable.. Transmission mount enforcer cups not required.