Honestly I would confront them because this is stupid.
I'm sure the money is already gone, either deposited and waiting to be spent, or immediately used to pay up their lapsed bills. Or I suppose, to get her whatever she wants with it.
I'm trying to convince dad to keep the car. He seems to agree that we should. Guess we'll see. All I know is that mom wasn't happy last night when she learned he gave away her car.