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 Approved Equipment for Collision Repair Warning in the
Preface section.
Warning: Refer to Glass and Sheet Metal Handling Warning in the Preface section.
Disable the SIR System. Refer to SIR Disabling
and Enabling.
Disconnect the negative battery cable. Refer to Batter ...
Rear Spring Insulator Replacement
Removal Procedure
Raise and suitably support the vehicle. Refer to Lifting and Jacking the
Vehicle.
Support the rear axle with a tall jack stand near the shock absorber.
Remove the lower shock bolt. Refer to Shock Absorber Replacement.
Using the tall jack stands, slowly lower the rear a ...
SIR Identification Views
The SIR Identification Views shown below illustrate the approximate location
of all SIR components available for the vehicle. This will assist
in determining the appropriate SIR Disabling and Enabling for a given service
procedure, refer to SIR Disabling and Enabling.
Front End Sensor-- ...