Obviously don't visit this URL if you do not want to know in advance what the cars available at each level up are and how much in credits they will set you back.
But alternatively, it could be a good way of managing the credits as you are levelling up, so you know how much you need for your next ride.
http://www.supercheats.com/guides/forza-motorsport-4/the-level-rewards-car-list/
But alternatively, it could be a good way of managing the credits as you are levelling up, so you know how much you need for your next ride.
http://www.supercheats.com/guides/forza-motorsport-4/the-level-rewards-car-list/