A policeman pulled over a car and strolled up to the driver's window:
"Excuse me sir, but do you know that you're driving without a rear light?"
The driver jumped out, ran to the rear of his car and let out a whimpering groan.
The driver seemed so genuinely distressed that the policeman took a sympathetic view:
"Don't take it that hard; it's not all that serious an offence..."
"Isn't it?" the driver cried, "Where's my caravan gone?"