So let’s say I have about 10 good years left on my Honda Accord, which gets like 32 hwy/23 city. I’d like to trade it in for a Prius. So I drive my gas-guzzling Accord to the Toyota dealership and trade it in for a nice green Prius. The dealer then sells the Accord to Joe the Plumber who continues to drive it for the remaining ten years of its life.
Why is it better for the planet and all that for him to drive it for the next ten years than for me to be driving it?