I am not sure what the issue is here, I lived for many years in Germany with a UK car and the speedo in mph. You quickly realised that 50kph = 30mph, 80kph = 50mph and that 120kph = 75mph.
I agree though that it is another oversight (or cockup) by Volvo with the user interface that doesn't seem to be properly integrated across the various displays and functions.
Never had a speeding ticket in all the years I lived there, now in UK that is a rather different matter
