the 710 joke

A few days ago I was having some work done at the local Ford Dealership. A blonde came in and asked for a seven-hundred-ten. We all looked at each other and another customer asked, "What is a seven-hundred-ten?" She replied, "You know, the little piece in the middle of the engine, I have lost it and need a new one." She said that she did not know what it was but this piece had always been there. He gave her a piece of paper and a pen and asked her to draw what the piece looked like. She drew a circle and in the middle of it wrote 710. He then took her over to another car, which had its hood up and asked, "Is there a 710 on this car?" She pointed and said, "Of course, it's right "there."