Cars should, in my view, not require any kind of fettling these days…even having to stop to fill them with fuel is a total pain (especially at £1.01 per litre). I take a similar view of having to fill the windscreen wash tank…ok, the water is free, but it’s still an unnecessary hassle.
Today’s invention is a water recycling system for car windscreens. Wipers would, instead of firing the water off sideways onto unsuspecting pedestrians, deflect it down the screen into a gutter at the base of both front and back screens. (I’d also site the spray nozzles at the top of the screen…I believe in making use of gravity, whenever possible). Dirty water would pass from here to a very crude filter tank (to remove the bugs, leaves and some exhaust particulates)…maybe even by a combination of centrifugation and settling.
In a country where it rains every day, this would reduce the frequency of water tank filling to an acceptable once a year chore.
Use of a better filter would enable radiator top-ups to be taken care of automatically also.