The problem is that assembly line production mandates standardization of parts and materials as much as possible. The reason all original Model T cars are black is because at the time, the only paint that dried fast enough to allow assembly line manufacture was black Japanese enamel. To summarise, I think that the standardisation of car design was an inevitable consequence of practical engineering. It simply isn’t viable to produce widely varying car designs in the same plant, as the expenditure both in time and money to retool for each new design is prohibitive.

Only nowadays, with modern robotic assembly plants can any sort of variation take place at all, since robots are versatile enough to allow simple retooling. However, even today the most unique cars are the most expensive, not only due to the exotic materials used in their manufacture, but also due to the fact that such vehicles often require special assembly plants, or are even built by hand, and humans just aren’t that efficient at building things.

Of course, I’ve only mentioned car design, but this situation can be applied to any mass produced product. Until we develop a more direct way of producing goods (by which I mean nano-assembly and the like), we will be cursed with beige boxes, so to speak. Or to put it another way: you can have a product quickly, cheap or innovative, pick two.