Never, Never, Never ever ever ever go into a drug test without pre-testing or practicing. ASSUME you will be at least partially monitored if your going to court! Don't mess up court tests, court tests = your freedom as a human being (frickin nasty isnt it). Leave your door open at home, have your girlfriend watch and practice getting normal water into a cup like a smooth criminal. Do it until you figure out a way that is unnoticeable, and natural. Also, it is good to pinch ur fake pee into a cup slyly at first then let off a stream of ur real piss into the toilet to get that natural waterfall sound. I dont know anyone who can pee just enough to fill 40 ml and stop without finishing the stream. (They'll listen for that at court, always assume the tester is the biggest asshole youve ever met in your life)

You wouldnt take an exam that determined your entire grade without studying, dont take a test that determines your entire life without some amazing confidence.