Depends on the state if it would be legal or not. May fall into the cell phone texting rules. I would think putting the 12.2 on the dash wouldn't be practical regardless because of it's size, etc. One of those floor mounts would probably be best all the way around. It isn't something I would do because it would just attract attention of the unwanted kind if you left it in the car plus if you get out and have to put it away in the trunk each time, too much trouble and if your car is being watched they would know where you put it. Those mounts tend to be enough of an advertisement in and of it's self.