I found this months ago, while researching alt fuels - hedge my bets for the future if you will. Once I saw the E85 discussions here, I thought I'd post the link to the website I had been reading. iirc, the E85 retro kit ran about $2200.00 and the rebate was about $2000.00. I remember thinking 200 dollars for the E85 kit was a good investment however, I had read some differing opinions about E85.
I am not an Illinois resident, and I have not participated in any rebate program myself. I simply thought it was interesting and might promote debate.
"The Illinois Alternate Fuels Rebate Program is available to any resident, business, local government or organization in Illinois. It offers rebates to anyone using E-85 or biodiesel fuels, and for acquiring vehicles that run on alternate fuels."
http://www.illinoisgreenfleets.org/
Enjoy!