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 WarningInterior Lamps Dimming
This group includes lamps which may dim. This group may use a combination of
vacuum fluorescent illumination, LEDs and incandescent
lamps
HVAC control module, head assembly
Rear HVAC control module, head assembly
Radio
Rear seat audio
The instrument panel cluster
The PRNDL lamp, wit ...
Accident With or Without Air Bag Deployment - Component Inspections
Warning: Proper operation of the Supplemental Inflatable Restraint
(SIR) sensing system requires that any repairs to the vehicle
structure return the vehicle structure to the original production configuration.
Not properly repairing the vehicle structure could cause
non-deployment of the air b ...
Variable Effort Steering System Description and Operation
The Variable Effort Steering (VES) system or MAGNASTEER® varies the amount of
effort required to steer the vehicle as vehicle speed
changes. At low speeds, the system provides minimal steering effort for easy
turning and parking maneuvers. Steering effort is increased
at higher speeds to provi ...