I believe that there are over 40 cars in the game, and the game comes budled with the Ultimate Speed Pack, which consists of the Bugatti Veyron Grand Sport Vitesse, McLaren F1 LM, Pagani Zonda R, Lamborghini Aventador J, and the Hennessey Venom GT Spyder.
One thing I do not like about this game that persuaded me to get the PlayStation 3 version of the game was that there is no available DLC. The Wii U verson is missing out on the Movie Legends Pack, NFS Heroes Pack, and the Terminal Velocity Pack. That means you can get 15 extra cars on the Xbox 360 / PlayStation 3 / PC versions of the game, AND get the Ultimate Speed Pack for just $10 more. You can also get the Dodge Charger SRT8 on the other versions too.
I will be doing a review of the PlayStation 3 version as well as a review of the PlayStation Vita version of the game.