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 ...
Installation Procedure
Align the rocker inner panel.
Clean and prepare the attaching surfaces for spot welding.
Apply structural adhesive to all attaching surfaces.
Position the rocker inner panel on the
vehicle.
Verify the fit of the quarter outer panel
Clamp the rocker inner panel into posi ...
Scheduling Service Appointments
When the vehicle requires warranty service, contact your dealer and request an
appointment. By scheduling a service appointment and advising the service consultant
of your transportation needs, your dealer can help minimize your inconvenience.
If the vehicle cannot be scheduled into the service ...