Many North American gamers reported problems after purchasing the Gran Turismo 5 DLC packs released today, as the content they bought didn’t seem to appear in the game.
The reason for the trouble is that the DLC for Polyphony Digital’s racing simulator don’t work like your usual DLC. You actually need to install them manually from the in-game menu of Gran Turismo 5. I don’t know the reasons for this additional step, but that’s just how it is.
After purchasing and downloading the packages you want, you’ll have to start Gran Turismo 5, go to the bottom right of the initial menu and press on the big red DLC button, that will bring up an installation screen and will finally let you enjoy the content you purchased. It’s a bit convoluted, but it does work.