how do i talk the mother inlaw into leting my fiance buy this? lol

Permission ??? What's that !
well it was my mother inlaws idea that since we are both in college we should stay at their house to make it easier on us. But we had to agree on letting her in on any big financial decisions. Lol she still thinks I should sell my duster and get a newer car. Lmfao never going to happen.