Sometimes the cold hard math makes it seem worse than it is.... Sure in some objective sense you're losing (probably) quite a bit of money, but if you're the sort that always has a car payment anyway and if there's no additional down payment involved, it's almost like you're just refreshing a lease.
Just tell your hubby that even if you waited until you payed off the old Z, it's not like the money each month you've been paying in payments is going to be freed up ... you'll just get a new car then anyway.
