Mazda is in the process of testing a car that runs on both hydrogen and gasoline (it’s a dual fuel system). They’re allowed to test the car on the public roads from Japan.
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Mazda Hydrogen Car to be Tested on Japan's Roads

Mazda’s New Premacy Hydrogen Hybrid Rotary Engine Car Takes to the Road
Mazda's newest hydrogen rotary engine will take to public roads in Japan for testing this year.
Mazda Makes Eco-Friendly Plastics from Biomass
Mazda Motor Corporation and Hiroshima University are researching together to develop a brand new “green” plastic material from cellulosic biomass. They want to use it in vehicles by 2013.
New environment-friendly fabric from Mazda
Mazda announced that it developed a new 'green' fabric, called "Biotechmaterial" which will be used for the interior of its future cars.
The Top 12 Greenest vehicles according to Forbes
Of the year's 12 most environmentally friendly 2007-model cars — a list dominated by tiny, economical models — six are hybrids. And two gas/electric hybrids.