http://www.polyphony.co.jp/english/list.html
GT5:P has shipped and downloaded 2.37 mil copies WW. (Ending June)
Last quarter it was at 2.23 so 140k in 3 months.
These sales aren't bad.
For comparison sake
http://vgchartz.com/games/game.php?id=6972®ion=All
VGC sold to consumer = 1.92 mil