Carl on 21 May 2010
Forza 2 is actually at under 4 Million sold.
3.5 Million to be precise. According to Turn 10, anyway.
The prologue for Gran Turismo 5 has outsold Forza 1, Forza 2 AND Forza 3.
Proof - http://www.vgchartz.com/forum/thread.php?id=91316