A police officer was staking out a rowdy bar one night for possible DUI violators. Come closing time, a fellow wobbles out of the bar, stumbles on the curb, and tries his keys on five different cars before he finds his own. The man drops into the front seat and fumbles around with his keys for a full three minutes. Meanwhile, the other patrons leave the bar and drive off.

Finally the man starts his engine and begins to slowly pull away. Of course the police officer is waiting for him. As soon as his wheels hit the street, the officer stops him, reads him his rights and administers the Breathalyzer test to determine his blood-alcohol content.

He gets a reading of 0.0.

The officer demands to know how that could possibly be. The driver replies, “Tonight I’m the designated decoy.”