What could these black specks all over my 77 Chevy Nova be?

[Renz]

They're black and won't wash off, but if I scratch at them they will come off. They're mostly on the hood and fenders of the car but it's basically all over the car including the roof. Could it be residue from the beginning of surface rust peaking through the paint? It seems to be continually building up on the hood.

 

[pontiacpowered71]

Are you parking under some kind of tree etc? I had these on one of my trucks and I washed it and used one of those 25 cent Walmart Scotchbrite pads and a heavy soap solution and they came right of with just a small amount of elbow grease.