WA State Wildfires - Camano Island

I had parked my passenger car on Camano for a week - driving my truck to and from the farm.  Was walking past and noticed the ash fall from the wildfires:

The ash is really gritty so I am going to take it to a do-it-yourself carwash place with a soapy pressure-washer spray. Don't want to abrade the paint down to bare metal.