Using the shoulder of a five lane freeway to pass a slow moving car in the left hand lane. Often this move is made by a douche bag that is driving a late model European coupe or sedan.
Son (sitting shotgun): Wow Dad! Look at that BMW pass that car up ahead.
Father (driving): Don't ever do that shit!
Son: Do what?
Father: The California slingshot, son.
Father (driving): Don't ever do that shit!
Son: Do what?
Father: The California slingshot, son.
by coined by T. Hoffman January 24, 2008