[mercedes308]

The amount of materials used to make environmentally friendly car, may be more than a conventional car. But lithium from batteries can be recycled, just the same as anything else.
The majority of environmental impact, with cars is when they are been built, not with use. So it's better to modify/clean up an old car than build new to the same standard.
Carbon footprint is also a red herring
in so much as they fail to consider the carbon taken up by the vegetation replaced by the fuel crop, that would not have been released into the atmosphere.
Electric vehicles powered by wind,hydro,solar are the future. And older vehicles modified to run on electric, even better.