Watch Viva Las Vegas for Free: How to Stream the Movie Online at 123Movies. . Lucky Jackson arrives in town with his car literally in tow ready for the first Las Vegas Grand Prix - once he has the money to buy an engine. He gets the cash easily enough but mislays it when the pretty swimming pool manageress takes his mind off things. It seems he will lose both race and girl, problems made more difficult by rivalry from Elmo Mancini, fellow racer and womaniser.