Man attempts to enter swanky restaurant. Maitre d' informs him that coat and tie are required. Man returns to car, dons coat, and tries once more to enter. Maitre d' says that a tie is also necessary. Man returns to car, opens trunk, takes out jumper cables, and arranges them around his neck. Heated discussion ensues, but maitre d' finally relents: "OK, you can go in, but just don't start anything!"
I remember exactly when and where I heard this joke. It was June of 1995. I was headed from Phoenix to Charlottesville to take part in an NEH Summer Seminar on the Philosophy of Science at the University of Virginia. As I was 'motorvatin'* in my '88 Jeep Cherokee past Knoxville, Tennessee on Interstate 40, old Paul Harvey (1918-2009) came on the air and told the above joke.
Now you know the rest of the story.
_______________
*'Motorvatin' borrowed from Chuck Berry's Maybelline.