Horn
To sound the horn, press the center pad on the steering wheel.
See also:
Playing an MP3 or WMA (in Either the DVD or CD Slot)
If a disc is inserted into the top DVD slot, the rear seat operator can turn on the video screen and use the remote control to navigate the CD (tracks only).
(Tune): Turn to select MP3/WMA files.
...
OnStar Mobile App
With an iPhone® or Android™-based mobile device, an OnStar mobile app can be
downloaded. The vehicle can be remote started, if equipped, or the doors can be
unlocked from anywhere there is cell ...
Connections
OnStar Hands-Free Calling allows calls to be made and received from the vehicle.
The vehicle can also be controlled from a cell phone through the OnStar mobile app.
See www.onstar.com for coverage ...