After you beat Razor, you find out that Mia is a spy and you enter a level 6 pursuit in the BMW. I've got the profiles of that type of cop on the MW cheat page. You can't escape this type of pursuit because there are cops everywhere. What you have to do is survive for a certain amount of time until Mia calls saying they cleared up the rubble by the old bridge and your car should be fast enough to jump it. Go to the old bridge (It's near Rosewood Stadium) and there'll be a minimovie where you jump the bridge and clear it whilst all the cops crash into eachother and fall.
After that, you can do whatever you want really. What I advise doing is completing the game 100% by doing every race, every milestone and every Lifetime Pursuit record on the rapsheet (It says I've completed my rapsheet 100% but I'm still missing Police Vehicles Immobilized in a single pursuit) and every thing in the challenge series. And hey, if you do that you're better than me, I can't do the challenges so if you've got tips on those please tell me.
After that my friend, the world is yours...
