Judith Lewis IT seemed, at the time, like such a good thing for the planet: In the winter of 2005, I turned in my red, gashungry Jeep Wrangler for a near-new, diesel-burning Volkswagen Beetle. Inspired by a number of pioneering friends, I would fill my little green slug bug with a nontoxic, sweetsmelling fuel made from vegetable matter called biodiesel. Unlike cars that run on straight, unprocessed vegetable oil, my BioBug required no mechanical conversion. With a weatherproof shed and two 55-gallon drums, I turned my driveway into a home fuelling station. And there, in full view of my greenerthan-thou neighbours, I smugly filled my tank. Biodiesel smells not like French fries but clean and nutty; if you spill a little on your skin, no worries