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 WarningAir Hose Test
Caution: The air hose test should only be used on fully cured
urethane adhesive. Otherwise, damage to the urethane adhesive bead
could result in additional leaks.
Using a liquid detergent, diluted with water in a spray bottle, spray
the window at the edges. Begin at the bottom and grad ...
Removal 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 ...
Installation Procedure
Create 5 x 18 mm (4/16 x 11/16 in) slots for MIG-Brazing along the edges
of the front wheelhouse panel rear reinforcement as
noted from the original panel.
Create a 5 x 18 mm (4/16 x 11/16 in) slot for MIG-Brazing where front
wheelhouse front panel and front wheelhouse panel ...