Who is responsible if a car owner let an unlicensed uninsured driver sit in their car and they drove it and hit a parked car?

It is your car, so you will be responsible, however, this would be a good court case, because he/she actually "stole " your car and drove it. your insurance company and your lawyer will advise you what to do.

Another View: It would, indeed, be an interesting case. There is such a charge as "Permitting an Unlicensed Operator." The law considers the person behind the wheel to be the person in charge of "operating" the vehicle. If you allowed the unlicensed person to sit behind the wheel, then you'allowed" him to be in control of the car, whether they drove off without your permission, or not. You may skate by without a traffic charge but your insurance company is not going to be happy with you. r