Cars seem so full of gimmicky features these days. A friend's car yesterday stopped us when exiting because it thought we left behind belongings in the back seat - it was just an empty package. That was not something I would have ever thought a car would flag. It's not that fancy of a car (entry level SUV) but it is fairly new, it just kind of bothered me.
One reason I hope Slate does well - newer cars have too much useless tech across the board. At least with a sports car the gimmicks are part of the appeal. Entry level new cars should be simpler, modular, and cheaper. Just let me drive and stop trying to be so helpful.
The back seat thing is probably the things cars have been adding to try to combat those freak memory accidents when parents forgot to drop the baby off at daycare and left them in the car in the sun all day with disastrous consequences.