Yesterday I was having some work done at the car dealer. A blonde woman came
in and asked for a seven-hundred-ten.

All of the mechanics looked at each other, and one of them finally asked:
"What is a seven-hundred-ten?"

She replied, "You know, the little piece in the middle of the engine. I lost
it and need a new one. It had always been there."

The mechanic gave the woman 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 the hood up and asked, "Is there a 710 on this car?"

She pointed and said, "Of course, it's right there." 

Scroll down the page to learn the identity of the mysterious 710: