The guy who sold me my Impreza recovered from an embarassing situation pretty well IMHO.
He had me test one car and while I was out found out that another car with less miles and in better shape had come back out from a hold. He showed it to me and started it up, at which point the low-fuel light came on. He said "I like to demo the low-fuel light, it's kind of my niche as a salesman." Well, there was definitely low fuel in the car - 30 seconds later it coughed and stalled out (it was 20 degrees outside as well). He said "Ahh, you see! Low-fuel light works perfectly!"