Xbox 360 racer Forza Motorsport 3 has sold over 2 million units worldwide, publisher Microsoft announced today. Microsoft-owned developer Turn 10 is christening the milestone with the launch of new downloadable content, the "Nurburgring Grand Prix Circuit Track Pack" -- it adds the German grand prix circuit for 400 Microsoft points. The announcement comes only days after Polyphony Digital revealed its rival PlayStation 3-exclusive franchise Gran Turismo sold 55.45 million units across the whole series. The popularity of Gran Turismo, which has always been an internally-developed PlayStation platform franchise, helped drive demand for realistic console racing simulators like the Forza Motorsport franchise, which began on original Xbox in 2005. Turn 10 launched the second installment in May 2007 on Xbox 360, and Forza 3 followed in October 2009 -- the latter sold 1 million units in its first month alone.