Dangers of Dust
While wintery conditions are known to play havoc with your car’s paint and bodywork, it is misleading to think that hot summery weather offers a respite. Ultra-violet light seeks to destroy your car’s protective paint, reducing not only the protective qualities it offers to the underlying metalwork, but also fading its colour.
Invariably, dust will also settle on the surface. While you may wish to brush the dust away with a cloth, or a hand, resist the temptation. Ultimately, dust is abrasive and it will act like fine sandpaper against the paintwork, creating minor scratches that will dull the finish.
A better solution is to use plenty of water to wash away the dust, followed by a wash with a PH-neutral car shampoo, used with a dedicated wash mitt. The car shampoo (do not use washing-up liquid) will provide a suitable lubricant between the wash mitt, or sponge, and the paintwork, that should reduce the risk of scratching the paint to a bare minimum.
If discovered, very light scratches can be removed with a suitable polish but it can be hard work to apply properly, especially in warm weather. An orbital polishing machine tends to be useful for this task. To help protect against further scratches, as well as UV radiation, apply a separate wax product to the paint afterwards.