FWIW only had this issue once with my 3.7 Roadster mainly on the tacho nearest to me being part of the Mustang instrument module used by MMC for this model.

I think I can explain the reason though. It was a cold but humid winters day albeit with dry roads. I had the heater full on with top down. This would have lead to big temperature difference between front and rear of instruments hence warmish humid air causing condensation on inside of cold glass.


Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone