I think Brandon's reply is about right. Shouldn't be too bad. But of all places - why THAT communist cesspool? I HOPE it's some kind of classic car that you can't get anywhere else? That would be a decent reason.....
I've had a couple bought out of Illinois. I had to have an Leo come out and verify the vin with the title and give me paper work.
Im pretty sure this is only if your buying a car from an individual.
If you buy it from a dealer, then you don't have to go through this.
In addition to the normal excise tax and registration fees that are due on any car, if you did not pay Indiana sales tax, the BMV will be collecting that before the issue your plates and registration. The IL dealer should NOT collect IL sales tax on the purchase.