Art... I know that the process can be complicated, depending on what is available to the kitmakers. Yes, as you point out, the "old school" way of doing it (taking photos and measurements off an existing car), then hand-carving a master, as they used to do, always includes the possibility of human error. Absolutely. But I was talking specifically about the "new way" of engineering a model kit... an instance where good, modern, 3D scan files of the real car are available to the kitmaker. In that case, I don't see how scaling down the files can possibly need any sort of "interpretation." Numbers are numbers, and a ratio (1/25, for instance) is a ratio. Yes, there would still need to be concessions made to accommodate the injection-molding process (for example, obviously the thickness of sheet metal cannot be accurately recreated in 1/25 scale, it would be paper-thin). But if modern 3D scan files are available, it would be impossible to make a mistake as far as overall contours, proportions, positioning of the B pillar, wheel opening curvatures, slope of the windshield, etc.