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 WarningFront Side Door Window Rear Guide Replacement
Front Side Door Window Rear Guide Replacement
Callout
Component Name
Preliminary Procedure
Remove the front side door trim panel. Refer to Front Side Door Trim
Replacement.
1
Front Side Door Win ...
Exhaust Manifold with Catalytic Converter Replacement (LUW)
Exhaust Manifold with Catalytic Converter Replacement
Callout
Component Name
Warning: Refer to Protective Goggles and Glove Warning.
Warning: Refer to Exhaust Service Warning.
Preliminary Procedure
...
Transmission Control Replacement
Transmission Control Replacement
Callout
Component Name
Preliminary Procedures
Remove the front floor console. Refer to
Front Floor Console Replacement.
Disconnect the range selector lever cable. Refer
to Range Select ...