Technology to save kids in hot cars exists. So why isn’t it in every vehicle?

At a car dealership a couple of months ago, Miles Harrison's 8-year-old daughter climbed into the back seat of a parked sports utility vehicle that a salesman was showing to the family. What happened next startled Harrison: As his daughter was exploring the back, the salesman got out of the car and shut the driver's door behind him. Suddenly, "the loudest horn you could ever imagine" started blaring, Harrison said.
Read more: https://www.nbcnews.com/news/us-news/technology-save-kids-hot-cars-exists-so-why-isn-t-n1038281?source=Snapzu