Apparently there is also a risk of wet seats, carpets and trouser legs if the windows are frequently left open during heavy rain. We have automatic wipers and headlights etc. (what for I don't really know, I just wish we had foglights that would not switch on unless it REALLY was foggy).
I am surprised that a device to 'automatically close windows left open while it is raining heavily' must be available for those people who are prone to leave their widows open frequently during heavy rain - maybe the automatic wiper sensor could be used, but that may mean that the windows will be continually opening and closing during light rain but automatically open themselves during a downpour, oh well back to the drawing board.