Joke

Police in a sleepy town have gotten accustomed to making their quotas by sitting outside the town bar snagging drunk drivers. One night, as everyone is walking out, the cop sees his clear target. The man stumbles out of the bar at closing time, nearly falling flat on his face twice, drops his keys half a dozen times trying to unlock his door. Sat in the passenger seat for a solid minute before realizing his error, repeated the inability to unlock his driver's side door, and finally, was the last person to leave the lot. He barely made it half a block up when the police pulled him over.
The officer gave him a field sobriety test, which he passed with flying colors, followed by three breathalyser tests, all of which came back "0.0".
"I don't get it. I saw you leaving the bar. You were clearly drunk!"
"Oh that? I'm the designated drunk tonight!"