One of my biggest criticisms of mainstream environmentalism is that it often gets its priorities wrong because it fails to see the bigger picture.
When it comes to automobiles, there far is too much attention going to the
vehicle and not enough attention to the
transport system as a whole.
The automobile is just one cog in the industrial complex that is the modern transport system. This system consist not just of automobiles, but highway systems, refineries, gas stations, parking spaces, etc. but most importantly, the cities that are designed to accommodate cars.
After 100 years and trillions of dollars spent on R+D, modern automobiles are already highly optimized, and are fast approaching fundamental limits. It is practically impossible to achieve a 10-fold efficiency improvement on a Volkswagen Polo BlueMotion or a Prius, at least not without paying a high penalty in price, complexity, comfort, useability and safety.
Therefore, the focus should not be on building greener cars but on using them smarter. In my opinion, the lowest hanging fruit is city planning. A 10-fold decrease in energy consumption
can be achieved by designing greener cities, and it doesn't require complex technology and resource depletion, just time and willpower. Hong Kong is a good proof of concept; it's no secret why it spends an order of magnitude less energy per capita on transport than North American cities.
Unfortunately unlike car companies, cities are run by politicians, who have little stake in investing in long term improvements, but the problem will solve itself once the oil price hits $300. High energy cities will then start to become uncompetitive and lose population to low energy cities.
Here is a sobering "bigger picture" analysis of green cars:
http://www.withouthotair.com/download.htmlPS. I ride a bike around town not because I'm a green hipster but because it's convenient and economical.