Car appreciation... the aesthetics, the engineering, etc

Agreed, love the biodiesel stuff, and not saying the Prius is the answer, but in the same way that Edison's early 'failures' proved a hundred ways not to make a light bulb, all of which were necessary precursors to designing a successful one, it is progress. The way coventional motor vehicles are manufactured benefits from a hundred years or so of streamlining. Of course something new is going to be more difficult, more labour intensive at first. Like the climate change deniers, people (e.g. the linked article, not you necessarily) will go out of their way to find 'evidence' to snub progress if it excuses their lifestyle choices or suits their money-making agenda.

I totally agree with your point about development and the need for the technology to progress, but buying a 2nd hand Prius does nothing to aid that. In order to contribute, one needs to be buying new to fund the development of the next wave of tech. If that isn't possible, there are better ways to be 'green' than a Prius, as stated above. Unless it's a statement of course.