Correct me if I'm wrong, but don't Police get some sort of "reward" when they crush a vehicle full of illegal goods?
But anyway, I'd hope that if you roleplay with the police well (pulling over when instructed, complying with their directions, having a friendly chat) in my eyes, would get you off the hook most of the time without them searching your vehicle as soon as they pull you over as you didn't try and get away from them. BUT, if what I mentioned above is true, then I believe the Police would strive to get that vehicle crushed despite the roleplay, so they can make a nice chunk of money for little work.