Car damage settlement problem?

You are correct! You do not have to get the vehicle fixed unless you still owe money (auto loan) on the vehicle. If you still owe money on the vehicle, the owners would be your father and the lender and an insurance company would have to look out for the lender also. If the vehicle is paid for, you have the right to get it fixed or accept compensation (the money) for the damage done. You do NOT have to repair the vehicle. The estimate is proof enough. If this is becoming that much of a hassle, I would contact his insurance company and let them handle it and also contact the police.