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 Battery N ...
Additional Maintenance and Care
Your vehicle is an important investment and caring for it properly may help to
avoid future costly repairs. To maintain vehicle performance, additional maintenance
services may be required. It is recommended that your dealer perform these services
— their trained dealer technicians know your v ...
Water Management Description and Operation
Plenum Water Flow Direction and Cleaning
A large percentage of water will flow off the windshield area into the plenum
chamber drain system and then down the outside on the
plenum to the underside of the vehicle. To ensure that the plenum chamber water
management system performs properly, the ...