finally i took a pick going over 130mph using the spedo on my comp screen. If you dont believe me now about not being a govoner then i dont know what will. Remember you can only set the speed trap to 130mph.
All you would really need to do, if you can't manage to take a picture while driving 140mph+, would be set the speed warning thing. There's no other way you can set it without actually driving that speed. Then take the picture of the MFD afterwards.