https://www.cnet.com/roadshow/news/why-tech-still-cant-save-kids-in-hot-cars/

There has been progress in the last year: GM Rear Seat Reminder has been available in about 20 of its models since it debuted on the 2017 GMC Acadia, and Nissan is launching Rear Door Alert in the 2018 Pathfinder. 

General Motors Rear Seat Reminder feature is available in about 20 models across its brands.