An exaggerated wide, low stance creates a meaner, more aggressive aesthetic. Often seen in concept cars and fanciful automotive illustrations, many modern automotive enthusiasts have adopted this look as way to modify their ordinarily performance-oriented vehicles in a show-car fashion. Most scholars point to 2009 as the birth year of the American stance movement, although its roots can be traced to the Japanese drifting cars, the Teutonic (mostly Volkswagen) scene, and the earlier American hot-rod culture. For more information, I'd suggest checking out Stanceworks or Canibeat.