the dlc cars

When u purchase the game from the store what do u get? Are there different games to choose. Like a collectors edition or something?

I see in the demo to purchase packs and what not. But that looks like buying the whole game.

Any help would be appreciated

http://forums.forza.net/turn10_postst21959_Forza-Horizon-2—DLC-and-Editions-List.aspx