Go to quick race. Select 'Hazyview Eight' and change opponents to 15 and laps to 20.
You don't have to finish first, but what you should do is just mess around and crash into as many cars as possible, because it will raise your aggresion points, as well as profile points.
I was on level 32 when I first tried this, and now I'm on 48 because I did it heaps of times.
And also, it only takes a few minutes if you are a good driver, and you use the Pagani Zonda R, and make the opponents have the 'same class' cars, not identical cars.
Xbox360Cheats.com is an unofficial resource with Xbox 360 cheats provided by members of the public. We are usually unable to test submitted Xbox 360 cheats, so please use them at your own risk.