Test Drive Unlimited fans can finally get their hands on the free "Launch Pack", which weighs in at 20MB and consists of two cars.
Them's be the Audi RS4 Quattro Saloon and the Nissan Skyline GTR R34, and while you will have to "buy" them in game, they won't cost you anything to download.
Atari has also launched a referral system, which could net you another couple of cars. All you have to do is dig a unique code out of the TDU packaging, get your friend to do the same and input the details.
If you're one of the first 10,000 codes, you'll receive a McLaren F1 LM and Pagani Zonda C12S Roadster. (Edit: providing you're in the US, it seems. Atari says the deal only applies over there. Tsk.)
In a related announcement, Atari also revealed that those of you who bought the game from a particular retailer in order to get the Lamborghini Gallardo will be sent the "token" to grab the car soon, as there's some final testing to do on the download.
(Edit: And Atari's been in touch about that too. Here's the official word on the situation in the UK: "All the exclusive pre-order cars are now available to download through Xbox Live Marketplace. Those of you that pre-ordered the game in the UK should receive your unique codes from the relevant retailer shortly if you haven't already done so."