"A Dirt 3 game code is only provided with graphic cards and APUs that were recently purchased and are advertised to be bundled with Dirt 3 - either through a sticker on the box, the card packaging, or advertised on the retailer's website. So if you were not specifically given a card to redeem Dirt 3 at the point of sale, have it packaged within the box, or was given it to you by the card manufacturer, then your card doesn't qualify for Dirt3."
Slightly misleading page but ohwell.