What are other alternative cars for someone wanting to help the environment?
Unfortunately there are not that many choices outside the Prius and other hybrids. Looking at the really small cars that are gasoline only, the ratings are not as fabulous as you would expect. The Yaris for example gets a great 9/10 for global warming pollutants, which are highly correlated with gas mileage, but only a 5/10 for smog.
I had the opportunity to drive a brand new Yaris the other day while my Toyota Highlander Hybrid was in the shop for a small recall repair. The Yaris was a comfortable ride. The Tesla is a little bit longer but definitely less tall.
Toyota is now reported that they will be expanding their hybrid line to smaller cars than the Prius, so perhaps there will be a Yaris hybrid in the future.