Dude just go, if you end up going through a checkpoint just ask the border patrol "am i being detained or am I free to go?" they can't make you answer any question. refusing to answer can not be used as reasonable cause. the law only requires you to stop your car at the checkpoint, it does not require you to answer any questions. If they ask you to step out of the car don't, if they ask you to pull over for further inspection don't. Just sit in your car and answer every question they ask you with "am i being detained or am I free to go?" they have to let you go.