A Toyota Prius uses a 38 module Nickel Metal Hydride battery which contains Lanthanum and a motor containing neodymium. These items are known as rare earth metals and as their name implies they are rare. The Prius is the largest consumer of these rare earth metals and unless the evils of science are learning to create these rare earth metals in a man made environment they will be gone in a short amount of time.
Lets also look at the fact that the other part of these hybrid vehicles utilize gasoline just as most american cars do. Gasoline is a large pollutant and generates more pollution during its transport and refinery stages than the less refined diesel fuel which most large trucks and European cars use. Not to mention diesel fuel can be substituted with waste vegetable oils. Diesel may also be substituted with bio fuels grown from the earth but in this day we need to be more concerned with feeding each other than driving around the consumer population of this Earth.
We should also look at who we are supporting when purchasing a Prius. A large conglomerate is operating under the Toyota brand name which supports warfare, capitalism to the greediest extent, and a list of not so pretty items on their budget list that anyone can find issue with.
On to solutions to the want for fuel and the need to be green. Not wanting is the very best solution but buying used is the best solution if it is needed. Americans need to loo closer at the diesel market and better yet the biodiesel market. Mercedes and VW diesel are simply tanks that will last multiple generations. If a truck is needed there are several to choose from such as Dodge with a Cummins engine or a Ford with and early or pre Powerstroke engine that can last a lifetime all the while working hard.
The only problem with Biodiesel, is we will need people to fry up some unhealthy vittles in order for us to stay propelled.