A police officer attempts to stop a car for speeding and the guy gradually increases his speed until he's topping 100 mph. He eventually realizes he can't escape and finally pulls over.
The cop approaches the car and says, "It's been a long day and my tour is almost over, so if you can give me a good excuse for your behavior, I'll let you go."

The guy thinks for a few seconds and then says, "My wife ran away with a cop about a week ago. I thought you might be that officer trying to give her back!"