If I let my vehicles go too long and not wash them they get a blackish film on them from the stinking trees in the yard. Maples, and Walnut trees. Someone 35+ years ago thought it would be a good idea to plant rows of them in the yard. I can't even start on all the drawbacks. I've got to start cutting down some of these monsters in the next year or so. And forget about getting a tree service to do it. Thousands upon thousands of dollars. Ughh.Hell, I can't get it clean inside, never mind out in the wind.