My god man. I don't want to be the negative bastard in the group but "Dream car"? That thing should be condemned. No matter what you do to it, other problems are going to continually crop up (leaks, rust, other hidden problems). For Pete's sake the only things holding it together are bondo and window sealant. Just tell her you couldn't fix it and have her sell it and get something reliable. Understand whatever she gets may not be a Mustang but that car (if you can call it that) is a certifiable nightmare.