My rambling thoughts only--
Reading between the lines here, it may not be so cut and dry for
@StarWarsGirl . You see, she did consult with her dad (the attorney) about negotiating price, etc., and he's been trying to help.
IMO, the real rub here is the point at which he can suggest only so much (based upon his years of experience), and allow her to fly out of the cage--to finish the deal in whatever way she wants. Or, maybe, based upon the intricate, financial negotiations involved in buying a car, he just can't let this deal go down, if it's not up to his standards. He may feel like he has to shield his daughter from a bad deal.
Yet, maybe there's more at stake here than the money . . .at a certain point, there is a fine line about when to cut the umbilical cord.