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 ...
Tail Lamp Replacement
Preliminary Procedures
Open and support the rear compartment
lid.
Remove the body side trim panel replacement in order to expose the tail
lamp pocket nuts. Refer to Body Side Trim Panel
Replacement - Left Side.
Tail Lamp Bolt (Qty: 2)
Caution: Refer to Fastener Caut ...
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 ...