Have you ever wanted to drive darius' or cross' cars, or your bmw in free roam, with no cops at all? do this, and you can.

first unlock whatever 'special' car you want to drive, then go to the quick race menu and choose race 31, then choose whatever settings you want for the roam (best to have no rival racers), then pick your car e.g: darius' audi.

then when the race starts, turn around and drive down the tunnel-thing to your right and when you reach the other side you will be able to free roam with that car and NO risk of cops at all! but make sure that you dont take the road instead of the tunnel or the race will restart.

have fun demolishing the city!