HYBRID cars made immediate headlines nearly a decade ago, when Honda and then Toyota introduced models that offered drivers moon-shot improvements in fuel economy and exhaust emissions. Today, those leaps of progress are proving tough to repeat: as new technologies develop and gasoline-electric powertrains become available in a wider range of models, the gains over existing hybrids seem more incremental than startling. And even when new twists in technology do arrive — developments that include plug-in hybrids, which can be recharged on household current to give them more driving distance on batteries alone — it may be impossible to give buyers a measure of how much the advances help because there is no test to measure their mileage. Read the article here: http://www.nytimes.com/2007/11/04/automobiles/04PLUG.html
Personally I think the biggest evolution is when it'll be REQUIRED BY LAW as a piece to each car for fuel economy. Or ok that's a little steep, how about making it the norm so that it's not just an extra but the standard, in the same way air bags, ABS, middle brake light, fuel injectors, catalytic converters, and the like became the standard.
