System approach to prevent car seat heat deaths

We got a new car, and I see it has 5 seatbelt sensors and a "check the back seat" reminder, so I can tell who isn't buckled in, and it dings everytime we get out the car to check the back seat.

But that's the issue, it dings "check the back seat" every time, and we all become inured to repetitive reminders that are frequently "false alarms" (ie no kids in backseat to begin with).

So I was thinking, with the seat belt sensor as part of the input to the system, and the fact car seats are usually always buckled, a seat buckle that remains locked once parked likely indicates that there is a car seat in the car.

Still that doesn't tell you if there is a child in that car seat. There are fairly sophisticated and expensive options, such as weight sensors which are calibrated to zero out the car seat weight, thermal sensors, cameras with AI. But if these were feasible solutions, they would likely have been introduced into cars.

I was thinking that there could be a state sensor which triggers if the back door was opened in the last two hours and/or since the last ride started; this trigger combines with the latched seat belt (and thus presence of car seat) and ONLY THEN triggers the "check back car seat, door was recently opened" warning.

Any other standard car telemetry we could feed to a simple processor processing the warning to estimate the likelihood there is a child in the back seat?