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 WarningRemoval Procedure
Warning: Refer to Cracked Window Warning in the Preface section.
Warning: Refer to Glass and Sheet Metal Handling Warning in the Preface section.
Note: Position the vehicle on level ground and move the front
wheels to the straight-ahead position.
Disconnect battery.
Remove quarter window ...
Body Waterleak Repair
Warning: If the vehicle interior is exposed to moisture and becomes
soaked up to the level of the sensing and diagnostic module (SDM),
the SDM and SDM harness connector must be replaced. The SDM could be activated
when powered, which could cause airbag deployment
and result in personal inj ...
Service Vehicle Messages
SERVICE AC SYSTEM
This message displays if there is a problem with the air conditioning system.
Take the vehicle to your dealer for service.
SERVICE POWER STEERING
This message displays if there is a problem with the power steering system. Take
the vehicle to your dealer for service.
SERVICE ...