"The passenger airbag in this car is activated only when a person over some minimum weight is in the seat in case anyone is stupid enough to let a child sit there."
When I was a kid, parents routinely let their kids stand on the front seat. Mine didn't...we had to stand on the floor in the back seat.
BTW, whonder how much all those airbags added to the price of the car? Last I heard (a while ago) they're $1500 @ to replace.