I should add that I'm told by people on the inside that everything is shot on site (no painting of panels outside the paint plant - Dylan can probably confirm) and the Oshawa paint line can shoot up to 10 different colours - at any time. So they don't have to do them in batches of the same colour (one of the Oshawa advantages). Now there may be some other logistics reasons for batching them - for that you'd have to talk to a plant engineer.
"BBOMG - More than just a car show.... It's an experience!"