Audi Handshake.
Originally uttered by my father circa 1984. He had recently purchased an Audi. We were on some sort of family trip. I’m riding shotgun; we’re on a two-lane highway. A car approaches, and to my horror, my father gives the driver the finger. I ask him why, and he replies, “I was just giving the Audi handshake.” Turns out my father was convinced that all drivers of Audis (as the oncoming car had been) greeted each other with the middle finger extended. Now used as a polite euphemism, as in, “Whoa, I think that guy just gave you the Audi handshake.”
– Soosan (December 2, 1998)