Does anyone really think that any all fossil fuel driven vehicle, be it car or aircraft or boat, has any long term future?
... or to put it another way: Does anyone really think that any fossil fuel has any long term future?
Small planet, finite resources. We really should be grown-up enough to save our resources for the future, investing them in real green energy instead of the smoke 'n' mirrors that are being demonstrated at the moment. The Pious saves a few mpg around town, but the energy cost to build it is substantial and its touring mpg is slightly worse than would be achieved without lugging the batteries and electric motor(s?) around. Wind turbines take many years to break-even and are proving far more costly (both financially and in energy terms) to maintain than the original sales blurb indicated. Even simple solar hot-water generation takes years to break even in energy terms and at present prices will, in any normal financial measure, recover the initial investment.
There are essentially two possible futures. In one, we now invest the finite resources we have in the best way we can to create a (lower) standard of living that is truly sustainable for the future. In the other, we continue to live out our orgy of consumption, deluding ourselves that science and engineering will make it all OK - until one day we wake up to find a denuded earth can no longer supply our gluttonous desires. Sadly, the first is, I suspect, politically not viable.