I have dealt with this many times with customers car while being a detailing business owner.

Fingernail polish remover will safely remove the excess paint off the factory paints surface and glass without harm. Pour the fingernail polish remover on to a microfiber towel and rub lightly and let the product do the work. Like Magic the white paint comes off with ease. Polish the factory paint as normal.

Warning do NOT use this product on plastics or rubber ONLY the metal & glass surfaces.

The sooner this is done the easier the job.