I to have this problem. I ended up doing 1/4 mile runs down the major road by my house. Blew all the ash right off. When I got back I hit my truck with my lambs wool duster then DS. I did this last night.
This morning I had to do it again ( luckily no moisture overnight ) but 2nte I see this happening. I ended up laying on a heavy coat of Buttery Wax ( no PC also )
Hopefully it helps. The ash has subsided alot this evening. Here's what I woke up to.. Mt truck and the wifes car I just got done spending hours working on.
PS.. I am also 35+ miles west of the fires