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 WarningHeadlamp High/Low-Beam Changer
(Headlamp High/Low-Beam Changer):
Push the turn signal lever away from you to turn the high beams on.
Push the lever again or pull the lever toward you to return to low beams.
This indicator light turns on in the instrument cluster when the high-beam headlamps
are on. ...
If a Tire Goes Flat
It is unusual for a tire to blow out while driving, especially if the tires are
maintained properly. See Tires. If air goes out of a tire, it is much
more likely to leak out slowly. But if there is ever a blowout, here are a few tips
about what to expect and what to do:
If a front tire fails, ...
OnStar Additional Information
Transferring Service
Press to request account transfer
eligibility information. The Advisor can assist in canceling or removing account
information. If OnStar receives information that vehicle ownership has changed,
OnStar may send a voice message to the vehicle, requesting updated account i ...