at the title screen where it says press start enter your cheats
The Xbox 360 does not have cheat codes, so you can't.
While you are in career mode, or quick race mode.
get nfs 4 the ps3 graphics r better an u can get cheats 4 it nvm wat he just said all you gotta do is find the cheat you want go into career go into code entry enter secret code and type it in. But...
hit select then type hippt101 and then hit enter and type 4563