Once? I meant twice.
1) I was having sex in a car at a dead end. Police came by, so I turned on the engine car and blasted it. The cop car had to make a 3 point turn, so I quickly parked my car, turned off the engine and hid under my seat.
2) There was a road block in front of me, I was drunk, so I thought it would be a good idea to go on the opposide side of the road to escape. There was a cop car waiting for imbeciles like me to do just that. About 5 seconds into the car chase, I realised that I was being dumb and pulled over. The cop car did not have a breathlizer machine, so I got away scott free again.

The End.