If you plan on getting a picture of the speedo while you are doing 180-190 on the street do not take your hands off the wheel. If you really feel the need to do this, figure out a way to mount a video camera in the car pointing at the speedo. Also don't even ask one of your cop buddies to clock you, you'd be putting them on the spot. If they helped you they could get in trouble, if they didn't help you they might be worried that you would get mad at them and if they didn't try to stop you or tell on you they could get in trouble, not a position you should put your friends in. If you decide to do this be carefull, I like your posts and if anything at all goes wrong at those speeds you won't live through it and I wont be able to read anymore of your posts.