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 WarningRear Compartment Lid Lock Cylinder Coding
The rear compartment lid lock cylinder uses 7 of the 7 cut positions. The tumbler
positions are staggered from side to side, 4 on one side and 3 on the other, are
not self-retaining, and are not snap in.
Note: All lock cylinders for side milled keys have right and left
tum ...
General Plastic Repair
Warning: In order to reduce the risk of personal injury when exposed
to toxic fumes while grinding, cutting, or applying repair material on any type
of sheet molded compound or RIM rigid plastic, observe the following guidelines:
Work in a properly ventilated area
Apply protecti ...
Strut and Shock Absorber Inspection
Note: The strut assembly DOES NOT have to be removed from the vehicle
to perform the following inspection procedure.
Note: A light film of oil on the top portion of the strut is normal.
DO NOT replace the strut for this condition.
Condition 1
Oil or fluid residue only o ...