St. Louis man builds engine that runs on vapor

After reading this story my mind was blown. I'm not a mechanic, but Bill Cain is. He's been rebuilding cars since he was a teenager. Recently he built an engine for a 1970 Plymouth Fury that recycled unused gasoline from the engine and converted its waste into power. This turns a 20 mpg engine into a 100 mpg engine. Let me state that he built this in the repair shop he owns. The story itself is actually very well written and gives us a taste of Bill Cain the man and his innovation. While not totally new, the idea seems to be working and there are experts who think it's viable. This is the kind of thinking we need while harder to develop alternatives are still in the planning stages. My only hesitation is, if a self-taught mechanic in St. Louis can do it how come none of the automakers have thought of it yet?