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 body lock pillar 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 a 50 mm (2 in) backing plate from the unused porti ...
Environmental Fallout (Acid Rain)
Caution: Refer to Clearcoat/Ultraviolet Screeners Caution in the
Preface section.
Note: Always refer to the manufacturer's packaged instructions for
the detailed procedures of materials used for compounding and/or
polishing.
Since the severity of the condition varies from area to area, proper ...
Emergency
With Automatic Crash Response, the built-in system can automatically connect
to help in most crashes, even if help cannot be requested.
Press to connect to an Emergency
Advisor. GPS technology is used to identify the vehicle location and can provide
critical information to emergency personne ...