They are permeating the state of Massachusetts, yet they may be doing more harm than good. I know their owners think they are above us all in protecting the environment. I disagree! Its like the Toyota Prius. Very popular here in MA because of its great gas mileage. The owners are thinking "I'm saving the planet by driving a Prius". The problem is, the carbon "footprint" to produce the car is much greater the one to produce a regular Toyota "Corolla" which is no "slouch" on gas mileage itself. Then there is the question of saving money on gas. Does it happen? I understand the Prius gets about 44-47 MPG. The "Corolla" gets around 35-37 MPG I think. The Prius, however costs 5-7 thousand more (probably more) than the Corolla. So my conclusion from investigating the hybrid is its not helping the environment or the consumer. The disposal of the battery will hurt its "greeness" and unless you drive "a helova lot" you will not make up for the premium price of the Prius in its greater MPG. Only in Massachusetts though, would these vehicles be so prevelent! Why does everyone else think?