Most regulars to OCDO are familiar with this video. It's great!
Bear in mind 'not talking to cops' takes practice, lots of practice.
You are fighting decades of conditioning that police are here to help you.
Parts of you will be convinced that if you could just 'level' with the guy or 'help him see your side' that he'll leave you be and let you go about your lawful business. Not true. If you want to talk to the cop that illegally detained you, shut up, ask if you're free to go, then walk straight home and write him a nice letter here. I promise he'll be around soon enough to read it
Watch me fail at my own advice to shut up here http://www.youtube.com/watch?v=XxP9yaEcNm0
Boy, the things I wanted to say/ask during that encounter. None of which would help my situation. Listen for the awkward pause at 1:15.