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 WarningRear Bumper Fascia Guide Replacement
Preliminary Procedure
Remove the rear bumper fascia. Refer to Rear Bumper Fascia Replacement.
Rear Bumper Fascia Guide Rivet (Qty: 4)
Special Tools
BO-594-A Hand Rivet Tongs
For equivalent regional tools, refer to Special Tools.
Rear Bumper Fascia Guide
Rear Bumper Fascia Inner ...
Event Data Recorders
This vehicle is equipped with an event data recorder (EDR). The main purpose
of an EDR is to record, in certain crash or near crash-like situations, such as
an air bag deployment or hitting a road obstacle, data that will assist in understanding
how a vehicle’s systems performed. The EDR is de ...
Installation Procedure
Drill 8 mm (5/16 in) for plug welding along the edges of the front
wheelhouse panel rear reinforcement as noted from the original
panel.
Drill 8 mm (5/16 in) for plug welding where front wheelhouse front panel
and front wheelhouse panel rear reinforcement overlap ...