Ford Focus 2010: Boot leak

The advice you have received is correct. While Ford is making an attempt to fix the fault it is doing what it is required to do under the consumer law. Unfortunately the law doesn't put a limit on the number of attempts to try and fix a problem, or a time limit in which it must be fixed, which I believe is a flaw in the system. In your case I think Ford has exhausted its chances and if it has still not been fixed it should come to the party with an alternative solution, one being a new car. I would attempt to talk to Ford's head office, present them with all of the information on what has been done to the car and when it was done, and attempt to negotiate a goodwill resolution.