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 WarningHome Page (Radio with Touchscreen)
Touchscreen Buttons
Touchscreen buttons show on the screen when available. When a function is
unavailable, the button may gray out. When a function is selected, the button
may highlight.
Home Page Features
audiopicturemovietelephoneelsmartphonelinksettings03/06/2012
...
Halogen Bulb Warning
Warning: Halogen bulbs contain gas under pressure. Handling a bulb
improperly could cause it to shatter into flying glass fragments. To help avoid
personal injury:
Turn off the lamp switch and allow the bulb to cool before changing
the bulb.
Leave the lamp switch OFF until th ...
Park Brake and P (Park) Mechanism Check
Warning: When you are doing this check, the vehicle could begin to
move. You or others could be injured and property could be damaged. Make sure
there is room in front of the vehicle in case it begins to roll. Be ready to
apply the regular brake at once should the vehicle begin to move. ...