For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningVehicle Positioning
At times, the position of the vehicle on the map could be inaccurate due to one
or more of the following reasons:
• The road system has changed.
• The vehicle is driving on slippery road surfaces such as sand, gravel, or snow.
• The vehicle is traveling on winding roads or long straight roads.
...
Symptoms - Squeaks and Rattles
Table 1: Rattle Coming From the Side Rail
Table 2: Rattle Under Vehicle at Higher RPM
Table 3: Thump From Rear of Vehicle on Bumps
Table 4: Glass Knock Coming From the Rear of the Vehicle When Driving Over
Bumps
Table 5: Rattle Coming From Door
Table 6: Squeak When Operating Doors
Table 7: S ...
Removal Procedure
Warning: Refer to Approved Equipment for Collision Repair Warning in the
Preface section.
Warning: Refer to Glass and Sheet Metal Handling Warning in the Preface section.
Disable the SIR System. Refer to SIR
Disabling and Enabling.
Disconnect the negative battery cable. Refer to ...