Has Toyota done anything to increase the "green" value of the Prius outside of vehicle engineering?

When you sit inside the new Toyota Prius, your rear side will be cushioned by the sweet touch of ecological plastics. That means the foam (and other plastic components throughout the vehicle) are plant-derived and carbon neutral, emitting less carbon-dioxide throughout the product lifecycle than plastics made solely from petroleum. The car also has no "new car scent"; rather, fresh grass clippings are taped to the air vents at the dealership.

Photo Courtesy of: Toyota