LAS VEGAS – When it comes to racing franchises, Sony has gotten a lot of mileage out of Polyphony Digital’s Gran Turismo games. The driving simulation has sold over 60 million copies worldwide since it launched on the original PlayStation in 1998. The most recent version, Gran Turismo 5, sold over 5.5 million copies globally last year. For the first time ever, Sony is expanding the game through downloadable content. The first DLC pack has already sold over 1 million copies at $9.99 per download.