I read somewhere that Tesla had an innovation to prevent this, but then couldn't Google it later. Did I dream that it can anyone else remember what I half-recall?
Rather than a car feature, what about one of those sensors that alert you if the object is too far? And force the user to explicitly acknowledge that it's intentional (for when you leave them with someone else).
How do you reduce false reports (e.g. dropped connections) enough that people won't shut it off in annoyance, though? For a technological solution to really work for the "break in routine makes someone forget a baby in the car" case, it has to be something that can be left in place forever once activated.
Good question. I wouldn't warn on a single broken connection, only after a couple of minutes without a signal, but I suppose even that could be annoying (e.g. kid sleeping on the next room).
Some GPS's have a specific chime and reminder for this when you get to your location if you enable the setting.
At first I thought you meant Nikola Tesla and was even more curious as to what it was.