During WWII, Europe experienced a tremendous fuel shortage in the civilian market because it was all diverted towards war.  Many people converted their vehicles to run on “wood gas” (smoke produced from a choked wood fire) or “town gas” (smoke produced as a byproduct of smelting) both of which are essentially carbon monoxide.  This gas has a low energy density and doesn’t lend itself to compression.  So, if you didn’t want to be stoking a fire while you drove around, you could just get a big canvas bag of gas and guff it into your carb and off you’d go.  They still do this in China with buses.  Yes you can buy a kit to run your car off of peanut shells and waste woodchips but why don’t people do it?  Because it takes effort.  Effort only becomes appealing when there’s a shortage.  Remember this picture, so you know what you’re looking at when you see one in about five years.

t-s-k-b:

Low-tech Magazine: Gas Bag Vehicles

http://www.lowtechmagazine.com/2011/11/gas-bag-vehicles.html