How screwed am I?

If I may play "devil's advocate", your problem is that the husband's transfer to you could have occurred without his wife's knowledge; that is, it might have been fraudulent. Plus, as Sedanman said, even if it wasn't fraudulent he had nothing to sell you in the first place. I think you are either going to have to get the wife to sign the transfer, or file a court suit to establish title to the vehicle. If you find there is some other way to do it, please post a follow-up because that would be very interesting.