To be fair, the outside of my cars can look similar to that very quickly in winter here. I live out in the sticks, lots of single track "roads" covered in farm overspill, tractor mud, general dirt etc.
I cleaned my car before going out in it the other day. It was a dry day, didn't rain. BUT roads still covered in rubbish. I got to my destination and the car was dirty so I had to give it a quick clean as it was taking part in a funeral procession at the request of a CCCUK member. Naturally it got dirty on the way home afterwards too, and is still dirty in my garage. Really no point cleaning my cars often as they'll just be dirty moments later when I drive them. Handily I hate cleaning cars with a passion, so it works out.