Review on Surface Mount Compass with 2.75-inch Dial in Black by Brad Russell

Works well - good enough in the car too. I drive a Passat and so far every compass I've tried has been completely inaccurate. This was close after calibration. It's still offset slightly when facing south, but close enough to get the job done. Comes with DC pigtails, but you need to provide your own plug that you need to connect. If you don't plug it in it still works, all you have to do is turn on the green night light. In the car at night it will be a bit distracting. Note: It's big. Much more than conventional car compasses. There's probably more than a baseball in your hand.