But even political/enviromental concerns aside it doesn't seem reasonable to me technically.

Suppose you can find and find and install new hardward to carry and regulate your fuel from the tank to the injectors. And is there a compatible fuel pressure regulator that has a diaphram that will stand up to E-85? But even then I don't think your computer can be retrained to provide E-85 properly to the engine as needed. Not the car might not run, but I bet the E-85 milage would be terrible because the computer wasn't managing it properly.

I have a flex-fuel minivan and don't use E-85 in it. At current prices, it would cost about the same per mile, but with the inconvenience of having to fill up more often at the few stations which carry E-85 even here in the corn belt. But I am glad I have the option only because if there ever were a big oil shock, wifey might still be able to get around when others can't get gas.