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 WarningFloor Air Outlet Duct Replacement - Right Side (Right Hand Drive)
Removal Procedure
Remove instrument outer trim cover -- right side. Refer to Instrument
Panel Outer Trim Cover Replacement - Right Side.
Remove instrument panel lower trim pad cover -- left side. Refer to
Instrument Panel Lower Trim Pad Cover Replacement.
Remove flo ...
Installation Procedure
Cut the rear side rail in corresponding locations to fit the remaining
original panel. The sectioning joint should be trimmed to allow a
gap of one-and-one-half-times the metal thickness at the sectioning joint.
Create a 50 mm (2 in) backing plate from the unused portion of the
serv ...
Removal Procedure
Warning: Refer to Approved Equipment for Collision Repair Warning in the
Preface section.
Warning: Refer to Collision Sectioning 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 Dis ...