This trophy will unlock after completing all 6 new races in all 5 movie pack cars. Terminal velocity races (marked by white wings on a red background) aren't needed. 4 are unlocked from the beginning, unlocking the Shelby GT500 requires you to beat it in a somewhat easy most wanted event and shutting it down afterwards. Difficulty isn't too high, some of the events may require a couple of tries though, the DB5 and Firebird especially, are painfully slow without any mods which means there is not much room for mistakes. Some of the new events also have really confusing tracks which might require you to try them again once you know where the track goes. If you completed all the events in the main game, this will be a breeze.