Well, even though any posts in here will be utterly ignored, since that is what big companies do now-a-days, but here are my suggestions:
1: Drifts (all of them) remove the train version entirely, its a * and poorly implemented piece of *, when it comes to other drift races remove the other cars and give them seperate maps to play on, the amount of times my 100k points have been ruined at the last second when the pissing AI just rams my car, it ruins the experience to have the AI doing so terrible at it, while still being able to do perfect drifts at 200+MPH, even on S type turns, i even need to slow down for those, but they don't, perfect drifts everytime.....that needs to stop.
What you need with Need For Speed: Underground and Underground 2 was awesome, drifting had its own map, its funny how no matter the difficulty of doing the drifts, the AI does it ALL the time perfectly, yet, when they get ahead, they slow down, they crash, they still do perfect drifts and when they get behind, they get massive turbo boosts in speed and even when i am going 200+MPH, they zoom past me, like i am standing still, so i dread to know how fast they were going, oh and they did perfect drifts that those speeds too.
2: Cops, I love this feature, but what i hate about it, is that the cops cars are not destroyable, i can make them crash into a pillar (the kind that causes us to go boom when they are going fast enough), but them...nope, just a little minor dent, if that, that needs to stop, they should be destructable, also, stop them from magically spawning, i had like 20mins of chase time because they kept spawning when there was 2 seconds left in the cooldown.
When it comes to the car parts and race challenges, i find it rather dumb, since i was able to beat easy, medium and hard races with my beginner car, the only time i began to get trouble, all i needed was to increase my speed by 1MPH and it became easy again.
Overall, the main problem with this game is not that its too easy or too hard, but the problem is the bloody Drifting with other cars about, You should make it just the player and just have the score you have to beat and other scores slowly creep up, cause i am SICK and TIRED of them ramming me and ruining my score when hitting me or me hitting them doesn't ruin their score, but it surely ruins mine.