I've talked about it in another post, having seen what these things go through for the contrast roof color at the factory, the cost is a bargain. The vehicle is grabbed off the line and brought into a single cell where the entire roof is hand sanded by 2 gents (after it is painted the body color), then taped off, then rejoins the paint line and goes through the paint booth again (robots go through all the motions to keep the timing the same but only spray when around the roof), then pulled back into the cell for the masking to be removed, and then it rejoins the regular line.
As a neat easter egg of sorts, if you look behind the headlight covers/grille area, you'll see where the masking plastic doesn't quite come together and there are two areas of the roof color sprayed on the core support area.
