And I think they look great! I got some to put on mine. Here's a thread discussing mostly where to get them, but also some talk about fuel efficiency. http://priuschat.com/forums/gen-iii...modifications/67338-2010-prius-mud-flaps.html
I would like to get as much deterioration of Gas Consumption as possible. I hope to get a Plug in Prius to maximize deterioration of Gas Consumption.