Thank you for your replies.
SpectGTD - I have that same concern...that the mother might become suicidal. I actually think though that this issue needs more media attention as opposed to less.
Creed - I understand your concern about not reducing it to a mere lack of focus issue!!!....I hadn't thought about the design issue, but you make an important point. In this case, the car seat was behind the drivers seat rather than the passenger side, so she wouldn't have reminded about the baby while driving. Maybe cars need to be designed to have an alarm sound if there is extra weight in the back seat after the driver has gotten out the door has been shut.
And cars are designed to be comfortable....so comfortable in fact that I think we tend to forget that we are moving a large chunk of mental down the road at high speeds and that the lives of others are in our hands. We are in our own little oasis in our cars. Add sleep deprivation to the situation and problems can happen.
Sometimes we push ourselves way too hard. We have laws against drunk driving...perhaps we should have laws against driving with too little sleep. Or under too much stress. So much of what we do everyday regularly is dangerous, but becuase we do it so often without incident, we get complacent - driving, cooking a meal on the stove, chopping vegetables, mowing the lawn, taking a shower.
Another thing that a person could do is put their briefcase in the back seat with the baby to force themselves to go back there...it would cause that that little ripple you mention....but people aren't going to do that because no one thinks they could make that kind of mistake.
At any rate, in the time I took to make this post, I could have written a letter to the powers-that-be suggesting a public awareness campaign about the dangers of hot cars (if people get reminded about this enough, that alarm in their brain should go off more often), changes in car design, etc. So a new project for me (NA - figure out who the power-that-be are).