The Elantra Sport Nav head unit is incredibly problematic. If you start the car, put it into reverse, the backup camera may or may not display. If it does, it often times will freeze the frame it is in, or crash to a black screen. The head unit will often times freeze and any action you took while it was frozen, it will complete after it catches up. i.e.

If you are trying to turn the volume up, it will put the volume in max when it catches up. Most times it freezes again, making it impossible to turn the volume down. Hyundai Motor America has deemed this to be a normal characteristic of the vehicle. It is only a matter of time for someone to be injured by this.