The Policeman pulled over a car and strolled up to the drivers window: "Excuse me sir, but do you know that you're driving without a rear light?"

The driver jumped out and 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 so hard, it's not all that serious an offence..."

"Isn't it" the driver cried, "Where's my caravan gone?"