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 WarningDeployment Inside Vehicle - Vehicle Scrapping Procedure
Deploy the inflator modules inside of the vehicle when destroying the vehicle
or when salvaging the vehicle for parts. This includes, but is
not limited to, the following situations:
The vehicle has completed all useful life.
Irreparable damage occurred to the vehicle in a non-deployment ty ...
Basecoat/Clearcoat Paint Systems
Warning: Exposure to isocyanates during paint preparation and
application processes can cause severe breathing problems. Read and
follow all of the instructions from the manufacturers of painting materials,
equipment, and protective gear.
All paint finish repairs of rigid exterior surfaces mus ...
Installation Procedure
Prepare all mating surfaces as necessary.
Align the front hinge pillar body reinforcement.
Create 6 x 20 mm (4/16 x 12/16 in) slots for MIG-brazing in locations
where you can not apply a resistance spot
welder.
Clean and prepare the attaching surfaces for spot welding a ...