So my cars speedometer stopped working and its going to cost a lot to fix. I do not intend to sell it anytime soon and its paid off so I'm not worried about re-sale. So Im thinking about buying a GPS unit that runs off the car that will show speed and tell me how to get place's cause I seem to get lost all the time. I also have a few road trips planned that it would come in handy. On the other end of the situation does GPS work everywhere and would it accurately gage my speed to where I wouldnt have to worry about being pulled over. Thanks in advance... discuss.