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 WarningImmobilizer Light
The immobilizer light should come on briefly as the engine is started. If it
does not come on, have the vehicle serviced by your dealer. If the system is working
normally, the indicator light turns off.
If the light stays on and the engine does not start, there could be a problem
with the i ...
Replacement Bulbs
Exterior Lamp
Bulb Number
Back-Up Lamp
921
Front Fog Lamp
H8
Front Parking/Turn Signal Lamp
7444NA
High-Beam Headlamp
9005LL
...
Roof Outer Panel Replacement (5HB)
Removal Procedure
Warning: Refer to Approved Equipment for Collision Repair
Warning.
Disable the SIR system. Refer to SIR Disabling and Enabling.
Disconnect the negative battery cable. Refer to Battery Negative Cable
Disconnection and Connection.
Remove all ...