Hello.
I have a 2005 X350 with Sat nav. There is a digital clock in the top right hand corner of the screen. The clock 'stops' when the engine is running/ignition is on. Therefore if the time displayed at the commencement of a journey is 20.39, the displayed stays at 20.39 throughout the journey. If I stop for ten minutes then start again, the time shows 20.49.
Any ideas?