What's a 710?

Yesterday I was having some work done at the
car dealer.  A blonde woman came in and asked
for a seven-hundred-ten.  They all looked at
each other, and the Mechanic 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."
Click here to learn the
identity of the mysterious 710: