If you replace a few components in your fuel system, you can run E-85 forever with no problems. Items required to run E-85 properly.
1. 33% larger injectors - Ethanol tolerant
2. 33% larger fuel pump - Ethanol tolerant
3. Anodize fuel rail (or get ethanol tolerant one)
4. Ethanol tolerant FPR
5. SS fuel line from tank to fuel rail
6. Ability to control fuel -DSMlink, SAFC, AEM
There are a few people on here that run E-85 daily with no problems. And a few people in CO have converted their WRXs to E-85. Now going on something like 10,000 miles with no ill effects.
Besides it's over 100 octane and it's cheaper than running race gas, so why not.
By the way, it's safe to run up to 23% E-85 with no ill effects no matter the age of your car. Cars made after 1988 can handle even more than 23%. Usually up to 30% without getting a CEL. All you ever wanted to know about E-85
http://en.wikipedia.org/wiki/E85