A factory-installed plug-in hybrid option — though I wonder if tapping a coal-powered electrical grid improves the Prius's carbon footprint that greatly. The real questions are: Who will prove more environmental in the court of pseudoscientific, envirosocial one-upsmanship — the owners who hold on to their existing vehicle, or those who trade in for the new, more fuel-efficient ones? And will the Bay Area see more violent, Prius-hating backlash?(Photo by Rick Audet)