[Merv and Sharon]

No Pills, not directed at any one and I did miss the point. Sorry about that. I wasn't sure why anyone would be using the GPS, when there were other options (e.g., my old T5 has an electrical take off). You have explained that well, however. I used my handheld to establish actual speed (and the iPhone?!) as shown on the speedo dial. Both GPS units were initially slow to register and then were affected by weather up here for some reason. If, as you say the GPS speedo system is faster and more responsive than mine are and they have 'onboard computer' capacity, that is great. Do some modern cars have this feature of GPS speedos? I seem to recall that Mercs have a 'distronic' system but I am not sure if that GPS based? I also had hassles with Smith gauges years ago on my MGA. They were never bright enough. Look forward to seeing the GPS set up in action.