See also:

Trunk (Sedan, Coupe)
WARNING! Exhaust gases can enter the vehicle if it is driven with the liftgate or trunk/hatch open, or with any objects that pass through the seal between the body and the trunk/hatch or ...

Weatherstrips
Apply silicone grease on weatherstrips to make them last longer, seal better, and not stick or squeak. See Recommended Fluids and Lubricants. ...

Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and GPS signal reception. Cellular reception is required for OnStar to send remote signals to the vehicle. ...