Another thought came to mind. When I bought the car early last year, I had the auto box oil changed by the garage. I'm not that sure that the appropriate N402 oil was used, in spite of me telling the garage what oil to use. What if another oil was used, and causing the box to run at higher temperatures, the amount of heat from the oil cooler would be more important therefore causing the coolant temp to be higher than it should?
And don't get me started on "you should have made sure that proper oil was used" or "do the change now", I know already
