rear view mirror with compass?

Is something with a compass showing the direction the car is going available? Our Sienna has a rear view mirror with a lighted letter to show the direction. I can't tell if one is available with any of the Prius v options packages. I'm not good with GPS navigation thingys--compasses I've tried in the car do not work correctly because of something in the car. I really need to know which direction is which.--