In general I agree with your article. Thank you for writing it. It brought me a lot of insight, and some new technologies to investigate. My response is focused where you left off
In the part of your article where they mention that 500 pounds at $4 a pound material goes into 3D printing a car, plus 10 hours, plus the moving bits and energy storage…
What you are missing is nearly the entire car can all be recycled. The pricy carbon fiber reinforced plastic can be remelted to make a new car. The delicate metal bits can be extracted by what is basically a large hot knife, cheap metal bits can be extracted when the melted plastics are filtered. The carbon fiber should not be degraded by the remelt process.
As the design changes, there will be major versions and minor versions.
Minor versions may be replacement components, or a section routed out and replaced.
Major versions might cost an extra $1000 to be remelted and reprinted with your existing components. During the remelting time you can pay for a roadster to minivan conversion and some extra plastic, or sell back some plastic to convert the minivan into a roadster.
Local motors has been promoting open hardware, and I welcome the innovation which will occur when mechanics have the design documents, instead of just measurements.