There are 2 separate issues here, criminal and civil. DUI refers to a criminal act--you were not driving under the influence, so you can't be guilty of that crime. (Theoretically I suppose you could be charged with aiding and abetting, if you provided him with alcohol when you knew he was going to drive, or told him to drive your car when you knew he was drunk, but I haven't heard of that actually happening.) Civil liability, however, can be derivative, meaning it was someone else's negligence that directly caused the harm, but you were responsible for making it possible. If someone else's car/property/person was harmed in the accident, you could be included in their lawsuit for negligent entrustment if you knew your neighbor was incompetent to drive safely when you let him take your car.
Did you loan your car to a known drunk guy is the question? If you did then you could be liable in civil court for damages to the other persons property.
If you told the drunk guy to drive, knowing that he was drunk or you provided him the alcohol and then let him drive your car, then you could be guilty of Aiding and Abetting a DUI.
I have only seen this type of case charged a few time in my 20 years of being an attorney and I have always gotten it dismissed.
Good Luck and if needed GET AT ATTORNEY.