Turn 10 Studios has today announced that its arcade cum simulation racer Forza Motorsport 5 has become the fastest selling Forza Motorsport game in the series’ history with more than one third of Xbox One owners buying the game since launch on November 22nd 2013.  To celebrate the momentous occasion Turn 10 Studios also announced that the Road America track will arrive as the first track add-on update for the game and is available now for free. Take a look at the trailer for a better taste of the track.