We have heard of some cases where the black plastic glass hinge bushings installed into the vista vent glass may split after the specified torque of 6 N.m is applied to the hinge attaching screws. This condition causes a water leak at the vista vent glass hinge attachment area.
To eliminate this condition, the specified torque has been reduced from 6 N.m to 3 N.m and the bushing compound has been changed. New P/N 20586100 has been assigned and new part will replace existing part in production and service as soon as possible.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.