The Cadillac Sixteen Concept was one of the greatest and most fierce appearances ever from cadillac. the Cadillac Sixteen Concept, which was unveiled in 2003. The model was “hypothetically” equipped with a 13.6L V16 concept engine. June 11th, 2010 The 2003 Cadillac Sixteen concept was a game-changer that never got the chance to change the game