I used to do that with my Garmins, but I now simply use the iPhone for Maps, "GPS", routes, MPH, weather, etc., etc.
Unfortunately, I need 6v-12v converter, or a 12v "power-pack" (like my DeWalt 2800 Peak Amp Jump Starter 1000-Watt Power Inverter with Digital Compressor, 120v power outlets, USBs, and, I think it can also whistle Dixie in 3-part harmony - part of my long-distance travel assurance/insurance).
Although, one of my 7"-screen Garmins also has back-up camera (that stays in/with my COE flatbed).
