Topic

When my Dad was stationed in the Far East with the Seaforth Highlanders, they were issued an order to remove all polished cap badges, because the kites were in the habit of swooping down and swiping the glengarries from soldier's heads. They were attracted to the shiny badges. Maybe a similar phenomenon causes birds to crap on cars.

Here's another theory. The waterless cleaners are also oil based, with some kind of surfactant. Perhaps the dust accumulation is due to oil's emulsifying effect, or the surfactants propensity for attracting dirt and dust, which is the reason that a large percentage of soaps are made up of oils and surfactants, mixed.

Why do birds crap on shiny cars? The answer is the same as why dogs lick their b@lls:
Because they can.

After a few waterless washes, the thing I found yesterday when water washing was how easily the crap came off the paintwork with hardly any any white drying marks, despite it being 'kin 'ot and very sunny.

You can't beat the old ways water and elbow grease
well i'm off to do some sun bathing

Actually, the waterless wash that I use seems to work fine, apart from the propensity for the car to attract dust a couple of days after it has been cleaned. I don't think I have ever seen a better shine finish.