A minor clever idea
The method I have of washing floors results in a bucket of clean soapy water, which I'm loathe to simply dump, but I don't always have some other use for it. Today I took the bucket out to wash off a particularly large and egregious splot of bird poop on the car, and I realized that I might as well give the whole car a quick wash down. Better than just dumping the water, eh? Now the car looks great (well, as great as it can manage, given that the paint is coming off in big patches), and I feel virtuous.