I found it really interesting that I've known some people that simply can't imagine a face on the front or the back of a car. I wonder what percentage of people can't see it. It seems obvious to most of us, the lights are the eyes, the bumper or license plate are the mouth/teeth, etc. It's like cartoon rules for faces, it doesn't have to make total sense just roughly.
I've heard that car manufacturers actually consider this effect too.