For the passenger inserts on my Taxi, I'm still trying to think of the best way to handle the combination of airbrushing, decals with white backing, decals with clear backing, and the possible use of white paint under the clear decals for the spots where they aren't over a clear insert.
One possible method involves putting decals down first, and then using frisket around them so I can spray grey up to the edge of them. Is frisket on decals a good idea? If not, then perhaps I can do all the decals I need, shoot a thin layer of clear (which would make it my second total layer) and then continue with applying the rest of the paint on the playfield.