Hyundai Rear Occupant Alert

The rear-occupant alert system will remind the driver to check the back seat when the engine is shut off if the back door was opened prior to driving somewhere with an audio and visual alert. The second alert is triggered by a motion sensor that sounds the horn, flashes the lights and sends a notification to the vehicle owner’s smart phone if an occupant is detected inside the back seat for up to 24 hours after the car is turned off. This system is available in the Sante Fe and Palisade models. 

https://www.hyundainews.com/en-us/releases/2383

https://www.youtube.com/watch?v=j8kfHgAr4-8

www.hyundainews.com/gallery/videos/33972 (ROA featured starting at 1:10)