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 WarningEngine Overheating
There is an engine coolant temperature gauge on the vehicle instrument cluster
to warn of engine overheating.
If the decision is made not to lift the hood when this warning appears, get service
help right away.
If the decision is made to lift the hood, make sure the vehicle is parked on
a le ...
Installation Procedure
Drill 8 mm (5/16 in) for plug welding along the edges of the service
panel as noted from the original panel.
Clean and prepare the attaching surfaces for welding.
Position the roof rear header (1) panel on the vehicle.
Verify the fit of the panel.
Clamp the roof rear header ...
Radio Reception
Frequency interference and static can occur during normal radio reception if
items such as cell phone chargers, vehicle convenience accessories, and external
electronic devices are plugged into the accessory power outlet. If there is interference
or static, unplug the item from the accessory p ...