See also:

Hitches
Use the correct hitch equipment. See your dealer or a hitch dealer for assistance. ○ The rear bumper on the vehicle is not intended for hitches. Do not attach rental hitches or other bumper-t ...

Add-on Electrical Equipment
The OnStar system is integrated into the electrical architecture of the vehicle. Do not add any electrical equipment. See Add-On Electrical Equipment on page 9‑112. Added electrical equipment ma ...

Auxiliary Roof-Mounted Lamp
If the vehicle has this feature, this button includes wiring provisions for a dealer or a qualified service center to install an auxiliary roof lamp. This button is located on the overhead console. ...