The answer is both yes and no."Yes" in that you could draw up a simple document, which you would have your father sign, stating that he will not allow anyone else to use the car and will take all reasonable precautions to prevent someone from using it. That would be enforceable, and if he violated the agreement and caused you to incur liability, you could sue him for reimbursement."No" in that while you could give yourself grounds to sue your father, as per the above, if he does lend anyone your car or is careless about securing it, or has irresponsible younger relatives living with him, then if something happens, you would probably still be liable or responsible, in that either you would be deemed to be negligent in allowing him to use it (if he had irresponsible younger relatives around, it's careless to lend your car to him), or if he intentionally or negligently did something wrong, it would the act of a person who had your permission to use the car, thereby making you liable. So while you can establish a cause of action against you dad, you may not be able to insulate yourself from liability, unfortunately.