Let me clear some stuff up.

E85 (85% ethanol, 15% gasoline) has less BTUs then gasoline, meaning you wont get as good gas mileage and it'll take more of it to make the same power. Yes it has a bit higher octane, but who cares unless you convert it to run only on E85.

There's a guy with an MkIII running it right now. Lots of information can be had. Check it out at http://www.supramania.com/forums/showthread.php?t=17780