Hot Cars and Children

There have been a few posts about hot cars and children but what I have seen regards a chime that goes off inside the car if a child is left in the carseat, however, if you are inside how will you hear this alert? What I would like to see is the same type of sensor that is used to turn the airbag off in the front seat passenger side based on weight but that is tied to smart technology or a true caar alarm. It can take 5 minutes for a car to become deadly to a child. If there is a specified amount of weight in the seat of a car that has not been attended to within 1 minute have an alarm sent to the owners smart phone. If it is not responded to by removing the weight within 1 more minute the car should sound an alarm that is not ignorable from inside the house. Something similar to the current alarm that alertss you to someone breaking into your vehichle. Maybe the S.O.S. signal as the pattern to truly gain attention.