I had one yesterday at a parade. A woman comes up to us as we are walking by (she walked right into the parade line, which is stupid right there!) and asks "are these cars solar?"
Now, she was pretty old. And to be fair a bunch of alternative energy vehicles had gone by a few groups ahead of us. So I can't fault her for just not knowing what she was looking at, but in the context of our thread here it was pretty dumb Also, the sound of 5 idling DeLoreans isn't exactly easy to miss.
However, maybe we should feel flattered that the cars look futuristic enough to garner such a question?