Microsoft is to launch the first Forza Horizon expansion pack on December 18.
The content will be released in addition to monthly car packs offering new rides for the upcoming racer.
No specific details about December's expansion were revealed, but design director Ralph Fulton told Digital Spy: "I'm not going to say any more than it's an expansion pack distinct from the car packs we ship, which we'll absolutely continue to do because we have a brilliant production pipeline that finds awesome cars and gets them into the Forza format."
The expansion will reportedly be available as part of a Forza Horizon DLC Season Pass.
Microsoft is also packaging a 'VIP membership programme' with the Forza Horizon Limited Collector's Edition, which will offer exclusive content including cars, VIP Rivals Mode events, in-game gifts and an expanded storefront.
Microsoft has confirmed an October 23, 2012 Forza Horizon release date on Xbox 360.