Fall-Line Motorsports Rear Upper Control Arm Bearing Set - G8X M2 / M3 / M4MADE IN THE USA. Rubber bushings in the G8Xs rear upper arms are the last weak link in an otherwise rigid suspension. The original BMW bushings yield to cornering forces applied to the suspension, resulting in camber and toe change that is not ideal for performance driving. Fall Lines kit replaces the soft upper control arm bushings with spherical bearings, enabling the rear suspension arms to move smoothly through their travel and giving the rear of