When each car is built by hand by a group of a couple dozen people, it's easy to make some tweaks here and there, especially when you're charging huge sums of money for it. Just look at the
Spyker C8, few cars have longer options lists than that. But big automakers don't take the boutique approach very often, and even
Rolls-Royce doesn't offer as much customization as, say, Dartz (although, in all fairness, Rolls-Royce does offer more subtlety, if less insanity). This production approach runs counter to the principals of manufacturing efficiency which have been gospel for the automotive industry since the Model T.