Boy.. I hear your frustration, but that's going to be a tough battle. I'm guessing you're not the original owner of the car. With that in mind, Unless it was under warranty from Ford when you bought it, the really don't owe you anything. Granted it sucks that this is happening, and you're the one catching all the crap on this, but I would almost suggest passing the car off on another person, most likely the same way the original owner did to you.
I hope I haven't offended you. I kinda got taken on my LS as well, but I like to work on cars, even when I know something bad probably happened to it before I got it. From what the original owner of my car told me was his dad nailed a deer with it. Western PA, go figure. I showed the car to a buddy, who does a lot of body work for Ford, and his comment was yeah, he did hit the deer. Again, and again, and again. He also asked me if I have any leaks. Yeah, passenger A post when it rains real hard. He was in a hurry, so I wonder what he saw, that I didn't. I don't know why I'm rambling here, but I guess the point is we've all been taken off gaurd at one time or another. The trick is if you learn something from it for the next go round.
Before you go thermo lobster nuclear on them, cover all the simple crap first. It's tough to do, especially when you think you're wasting your time. Like I said before, It's probably something simple. I hope I'm right!
I'll quit giving advice now, and get off my soap box... Geeze.. I'm starting to sound like my parents! THAT'S more scary than any sound a car can make!