Is it polish residue or dust from the surrounding environment?
Buy a car in a different colour.
We have an additional seasonal problem with Seagulls that nest between our chimneys and cover your car with generous helpings of poo.Sorry, it’s Pollen time.
Infuriating but light silver in the only answer, beyond just regular washing.
But we are in a seasonally bad time: worse at the moment than most of the year.
"Needs must."Well it would shift the bird shit, yes, but the the damage to the panels would be pretty bad IMHO.
Its a choice between a great looking car (and a degree of satisfaction ) for a bit ,in truth rarely more than a day for my black CLS or a less stunning silver that looks OK for a lot longer.
My previous car was Tanzanite blue which looked good for probably twice as long as black...so two or three days.