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:

California Proposition 65 WarningRadio Replacement (With US8)
Radio Replacement
Callout
Component Name
Preliminary Procedure
Remove the instrument panel center molding. Refer to
Instrument Panel Center Molding Replacement.
1
Radio Bolts (Qty: 4)
...
Rear Side Door Window Regulator Replacement (Hatchback)
Rear Side Door Window Regulator Replacement
Callout
Component Name
Warning: Refer to Glass and Sheet Metal Handling Warning.
Preliminary Procedure
Remove the front side door window from the guide. Do not remove ...
Starter Replacement (LUV)
Removal Procedure
Disconnect the battery negative cable. Refer to Battery Negative Cable
Disconnection and Connection.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
If equipped with a front suspension skid plate, remove the drivetrain
...