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 WarningInstallation Procedure
Cut the rocker outer panel in corresponding locations to fit the
remaining original panel. The sectioning joint should be trimmed to
allow a gap of one-and-one-half-times the metal thickness at the sectioning
joint.
Create 50 mm (2 in) backing plates from the unused portion of the
...
Radio Reception
Frequency interference and static can occur during normal radio reception if
items such as cell phone chargers, vehicle convenience accessories, and external
electronic devices are plugged into the accessory power outlet. If there is interference
or static, unplug the item from the accessory p ...
SIR Inflator Module Handling and Storage Warning
Warning: When carrying an undeployed inflator module:
Do not carry the inflator module by the wires or connector.
Make sure the air bag opening points away from you.
When storing an undeployed inflator module:
Make sure the air bag opening points away from the surface on which
the in ...