A while, back there was some discussion on adding a gps to the instruments available. I recently tried a different approach, and just used an old cell phone. My son had several old out-dated android cell phone around. The were the so-called 'smart phones', ie they had a digital touch screen. I took one, charge it up, and after turning it on deleted all his personal data. Then I turned on the internet connection, and it connected with the wireless internet in our home. (you could do this anywhere wireless internet is available. McDonalds, Barnes & Noble, etc). Once connected installed GoogleMaps (it may already be there), and then found some speedometer apps. About a dozen were available for a free download. I just picked one and installed it. Now the phone will display the speed of any vehicle it is in, and you can check your existing speedometer and odometer. It also does not care if you change the tire size or the rear end ratio. It can also be used as a GPS. You can even see how fast you can run!