Under-cowl paint color?

[Denis]

I'm talking about the color under the cowl panel, through the plenum openings where the wiper transmission is visible. On this original paint car, the area is clearly body colored with the wiper transmission black:



Yet I'm told that the factory assembly procedure included "black out" in the plenum area so that the wiper assembly wouldn't stand out so much. So I'm trying to find examples of cars to support this claim -- obviously the car pictured above doesn't, so maybe it's hit-and-miss or maybe it depends on assembly date or assembly line, or exterior color, or maybe it was just never done.