Charging more for metallics isn't uncommon; BMW, Porsche and Mazda (and probably some others) charge more for some colours than for others. As juddct pointed out, it's not as though the metallics are "free" on other makes and models; rather that they have a rough idea in advance of what percentage will likely be ordered with a metallic colour and simply spread their anticipated unit cost over all colours. In that sense, you actually pay more by buying a solid colour, since you're picking up the tab for someone else's silver paint.
I think this pay-as-you-go model is a little more prevalent in Europe because they're further along in BTO systems of manufacturing. With less finished inventory on hand less hedging of prices needs to be done. (This is purely speculation on my part, mind you).
-CW |