Not wanting to sound negative, but i think if the wrong color was applied to the trunk, it would be easily seen by the inspection department at the final stages (but i'm quite positive that the inspection between the different departments would have picked it up) of the assembly line and be corrected immediately, even if that was a sloppy job in the end, which was. The trunk is a place which can be easily seen by the buyer and then a negotiation would start with the dealer to deduct some
from the agreed final cost, due to the sloppy finished product. I understand about the quality job back then, but the ultimate inspection department is the buyer himself, so the dealers were costing the corportion additional money for these slips. Quality of parts or the quality of the car itself wouldn't make the buyer care, unless he had auto knowledge. I just believe they couldn't do such a sloppy job in the buyers' face. I think (and hope) that someone, some day, painted the trunk red, to cover the rust or scratches etc and used what he had there...
There is a fine article about a paint mistake at the Chrysler Lynch Road Assembly Plant
http://www.deadnutson.com/building_a_mopar.html