iStream Manufacturing Process

While reading the article, "From the master of speed comes a lean, green city car," I was confused as to why this article would be included in a supply chain management class, as it discusses the introduction of the T.25 and T.27, eco friendly cars that are smaller than the SMART car.  There is a brief mention, however, to iStream, a new manufacturing technique, so I delved a little deeper to determine what's so unique about this process.

iStream seems to be a component based manufacturing technique, where the chasis/platform of the car is produced in one area, and the fairings are produced elsewhere, before assembling the two together.  The advantages are that by using one platform for all models, and just changing the fairing, you are able to produce multiple variations of a car very simply, and put all of the components together (brakes, electronics, suspension, etc) on the chassis before attaching the body panels.  Additionally, making single piece, pre-painted, fairings that slip onto the car make for very easy assembly, repair, and modification.  This also enables production facilities to be significantly smaller, than with other auto manufacturers, as they are able to quickly assemble the finished product, with JIT delivery of components, minimizing works in progress.  If they were to include cradle-cradle design methods, discussed in the Herman Miller paper, in an attempt to use materials that are as eco-friendly as possible, it would be feasible to develop a car that does not have a significantly negative impact on the environment, while meeting price points that consumers are happy with.

One disadvantage I see with the iStream process is that I don't believe people buy cars on the exterior looks alone.  If all of the interior components are identical (frame, suspension, electronics, etc) and the outside of the car looks different, to me it is still the same car.  Would it be possible to incorporate the iStream manufacturing process, in a single facility, that offers multiple suspension options, or different engines for the vehicles?  I believe that although iStream factories are 80% smaller than regular auto manufacturers, the customizability of the products is significantly less as well.  Is there a way to offer different levels of customization for vehicles in a single facility, or would they need to develop multiple component facilities, each of which performs a different task, to get the level of costomization american consumers are used to?