The Toyota Prius dominates the market for dedicated hybrid cars, which are designed on hybrid powertrains and do not offer gasoline-only versions. Toyota's only competition has been from the Honda Insight, which was discontinued last year because of lack of demand. But the 2016 Prius faces an increasingly crowded market of plug-in hybrids like the Chevrolet Volt and Ford C-Max. And Honda, Ford and Hyundai are rumored to be planning new dedicated hybrid models in the coming years.