In principle anyone can participate in the Automotive X-prize, aimed at awarding the team that builds an efficient car that sells [see link].
In practise, however, the contest will only draw in teams from the USA and Europe. Also, the rules for the contest are not very clear.
This idea is very simple
and built around other motivations: an automotive design award for teams from the 'developing world'. Contrary to the X-prize, there rules are very clear:
1. the car must get 100 mpg
2. it must be a three person car (1 driver, 2 passengers)
3. most importantly, it cannot be 'technology neutral' as the X-prize is, but must instead work *entirely* on non-fossil fuels
3.1. either liquid biofuels such as ethanol, methanol, biodiesel or biobutanol.
3.2. or compressed biogas
3.3. or an electric car charged by solar or wind or any other renewable energy source
3.4. or any combination of the above
4. it must sell like hot dogs in the country of origin - and capture 5% market share after 3 years.
This is a difficult requirement, because it means that not-so-wealthy people must be able to buy it. On the other hand, these people from the developing world do not need luxury so much, they want functionality and hyper-efficiency (which can be very luxurious qua design)
The last rule is crucial because it is aimed at supporting the nascent renewables industry in these developing countries. These countries have the capacity to 'leapfrog' using green technologies, because they are not burdened by old fossil fuel infrastructures.
In India, for example, there are already 4 million biogas plants; in China there are 10 million; it would be easy to design a car around this radically green infrastructure.
Moreover, the developing world will be responsible for 80% of the world's increasing demand for transport fuels, by 2030 and for more than 50% of the world's growth in CO2 emissions.
Added to this: their economies are highly 'energy intensive' and high energy prices make them suffer most. So they're the ones who benefit most from a hyper-efficient car.
The time for them to leapfrog beyond fossil fuels is now. And a design contest aimed at teams from universities and entrepreneurs from Brazil, India, China or Africa might stimulate this jump. It might also give the world the idea that engineers from these countries are really capable of creative designs, and not merely copy or execute what's coming from the West.