She told him, “Every time I take any of my friends out in my car, after a while there is this terrible smell.  It never happens when I’m on my own.”

This quite intrigued the mechanic so he said, “Okay, lets go for a spin and see what the problem is.”

Off they went. She drove down a one-way street in the wrong direction at 60 mph, swerving and hitting the curb on both sides of the street.  She narrowly missed three pedestrians in pedestrian crossings, ran several red lights and just missed a policeman on street traffic duty.

They returned to the shop and she said, “There it is now; there's that terrible smell.  Can you smell it?”