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 WarningRear Side Door Upper Hinge and Lower Hinge Replacement
Preliminary Procedure
Remove the rear side door. Refer to Rear Side Door Replacement.
Rear Side Door Hinge Bolt (Qty: 4)
Caution: Refer to Fastener Caution in the Preface section.
Tighten
25 N·m (19 lb ft)
Reart Side Door Hinge
Procedure
Adjust rear side door as needed. Refer ...
Anti-Corrosion Treatment and Repair (Base)
Warning: When applying sound deadeners, or anti-corrosion materials
due care and preventative measures must be exercised to prevent
any material from being sprayed into door and quarter panel mechanisms such as
door locks, window run channels, window regulators and
seat belt retractors, as wel ...
Doors
Trunk
WARNING
Exhaust gases can enter the vehicle if it is driven with the liftgate, trunk/hatch
open, or with any objects that pass through the seal between the body and the trunk/hatch
or liftgate. Engine exhaust contains carbon monoxide (CO) which cannot be seen or
smelled. It can cause u ...