I tried one of those ebay repair kits on a 2007 fiesta, spent ages doing it meticulously. End result was still slightly messy as the fluid leaked under the masking tape slightly, and it did nothing to fix the heating element.
May have been bad application by me, or a rear screen beyond repair (there were a lot of breaks in the element), but I wouldn't jump to recommend it!
Unless anybody else has had success?
