Well, how many tanks are non-metal? I'm guessing only a few. Is the Prius a rare bird with the "bladder"? ( this is something I know very little about, what's it actually made of? ) Perhaps you refer to the meters or gauges? Well, I'm sure there are some non-metal parts there. In general though, I think all plastics and synthetic rubbers made after the mid-80's are ethanol resistant. I'll find out. I'm boosting to 75% ethanol in my non-flex car this week. I'm also confident that any degredation is a slow process, and the car in general will be worn out in a few years anyway.

How about the reverse? The majority of grapes are used for wine, not food or fuel. ( wine ethanol is nearly the same % as corn fermented ethanol... 12-15% per batch ) Would the world be better with less drunk driver "winos" if we diverted that grape ethanol to our cars? How much wheat and barley goes into beer vs. bread? Do people drink beer in lieu of eating toasted cereal for breakfast? I don't think so. So there's millions of gallons of ethanol that Budwiser makes instead of fuel, and that can be argued it takes away from the food supply. These are just questions to think about. Like my sig. says, I don't have all the answers. But my point is, I hope people look deeper. You can find fault with anything we do.
Thanks for reading. I appreciate the discussion and feedback. -John