A friend has recently bought an imported Mercedes. Won't be used much, it's for "Sunday best". As an import, the car is LHD and the speedometer is in kilometres per hour, not miles per hour. It'll be rather expensive to replace the speedometer with a one that shows MPH. So he was thinking of augmenting the speedometer with a car-specific GPS speedometer that shows MPH. I don't know a lot about such things. But a few moments googling comes up with:
Does anyone have any other suggestions, recommendations, useful websites etc?