Wood gas does present an interesting alternative in that it is far "Greener" than petroleum based fuels since it is carbon neutral (burning wood has the same emissions as rotting wood). My only problem is that it is not very efficient in the amount of space it takes up as a fuel. All the wood gas cars I have seen use a very large....ummm... wood stove (for lack of a better term) hung off the back of the car, and they all face problems with creosote build up in a fairly short amount of time. I do think it would be fun to build a pyrolization/steam/electric/solar hybrid though and enter it for the X prize if only for the shear Rube Goldberg nature of the thing. Can you imagine what some poor hapless car or truck would look like with all that stuff hung off of it? Then again, you could also use pyrolization to run two separate boilers- one in which the wood is burned and another that burns the wood gas, OR have a compound power source involving both steam and a small IC engine that burns the wood gas, and have them hooked to a common crankshaft. Hmm... Well... I gotta go prep for my calc final so I'll stop here for now. Otherwise I will spend all day thinking about this stuff.