[GeSmi]

Hi. New owner of m440i here. Had car valeted on drive by local travelling professional on Friday. On Saturday it rained (after a week of, by UK standards, scorching dry weather), and by the evening my car (and others in the street) had dried to a collection of pale sandy grit circles. Pictures follow

What's the simplest and safest way to sort? I have a pressure washer, hose, microfiber cloths etc but am worried that, for example, the pressure washer will gravelblast the car. I admit I'm looking for a shortcut having only had the car done properly 2 days ago.....

Any advice (apart from to keep the car inside....)

Thanks