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 WarningAccessories and Modifications
Adding non‐dealer accessories or making modifications to the vehicle can affect
vehicle performance and safety, including such things as airbags, braking, stability,
ride and handling, emissions systems, aerodynamics, durability, and electronic systems
like antilock brakes, traction cont ...
Vehicle, Engine and Transmission ID and VIN Location, Derivative and Usage
Note:: Graphic shows exemplary VIN.
The VIN plate is the legal identifier of the vehicle. The VIN plate is
located on the upper left corner of the instrument panel (I/P) and can
be seen through the windshield from the outside of the vehicle:
...
Exterior Lighting
The exterior lamp control is to the left of the steering column on the instrument
panel.
: Briefly turn to this position
to turn the automatic lamp control off or on again.
AUTO: Turns the headlamps on automatically at normal brightness, together with
the parking lamps, taillamps, license ...