http://www.youtube.com/watch?v=loC0sPsedgwI found a secret road which helps me to get past the hardest cop takeout level. the objective is to take out 20 cops in under 15 minutes, or 10 minutes if you want to dominate.
The problem is, that when you take out about 6 cops, the federal police with their spike strips come into play, and escaping them is much much harder. At least, it was, until now!
This video will demonstrate how to use a secret passage to your advantage to escape the police.
Car used: Chevrolet Corvette with all upgrades (this really is the fastest car in the game. If you tune it the way I do, you can dominate every race/event. It will accelerate faster than other cars while still being able to get the max top speed. Using this setup, there's a small trick that will work. Making a 90 degree turn at high speed, do the following: Keep pressing gas and a moment before you're into the corner, turn and then press nitro boost. It should shuttle you around the corner as if you were driving 120 km/h (47m/h) while you can actually be driving 250km/h or faster. True. You will loose speed, but not hit the corner.