Hi Guys,
I managed to get evans halshaw ford to take a look at my car for FREE yes FREE as they originally wanted £45 just to diagnose the problem and its turned out that its the Exhaust manifold that has a crack in it. They hopefully will cover it under the extended warranty fingers crossed! When its cold the crack is open then when it warms up the crack closes with the heat and thats why the screech noise stops! Hope the warranty comes good :-(