The rear outboard head restraints can be removed if they interfere with the proper installation of the child restraint.
To remove the head restraint:

Warning
With head restraints that are not installed and adjusted properly, there is a greater chance that occupants will suffer a neck/ spinal injury in a crash. Do not drive until the head restraints for all occupants are installed and adjusted properly.
To reinstall the head restraint:

If necessary, press the height adjustment release button to further lower the head restraint.
See Head Restraints on page 3-2.
Securing a Child Restraint Designed for the LATCH System
Replacing LATCH System Parts After a CrashBuying New Tires
GM has developed and matched specific tires for the vehicle. The original equipment
tires installed were designed to meet General Motors Tire Performance Criteria Specification
(TPC Spec) system rating. When replacement tires are needed, GM strongly recommends
buying tires with the same TPC Sp ...
Roof Rack System
Warning
If something is carried on top of the vehicle that is longer or
wider than the roof rack-like paneling, plywood, or a mattress-the wind can catch
it while the vehicle is being driven. The item being carried could be violently
torn off, and this could cause a collision and damage the v ...
Emergency
With Automatic Crash Response, the OnStar system can automatically connect to
an OnStar Emergency Advisor. The built-in system can automatically connect to help
in certain crashes.
Press to connect to an OnStar Emergency
Advisor. GPS technology is used to identify the vehicle location and ca ...