I could have sworn somebody replaced my disk with Need for Speed Underground 2.
Need for Speed Carbon is also very similar to Need for Speed Underground 2; It is always night time, one part of Carbon Canyon is a big city, the other is a mountain, the airport and the fact that you can challenge racers that you see in free roam. Also Need for Speed Carbon brings in a new drift system. I found that this drift system can be extremely frustrating to pick up, but after you've got the hang of it, it's not too bad.
Overall Need for Speed Carbon gets a 7.5 because of the shortness, for removing drag races from the game and the fact that it is so similar to Need for Speed Underground 2.