If you get it fitted at the dealer it'll be covered under the existing warranty. The cost 'was' somewhere in the region of €450 + fitting. I wanted it last year, but there was not one GT in the country or even one on route with it fitted.
Just bare in mind that this can only be fitted to GT's with the 3.2 V6 and the JTD engine (6 speed box).
Quite a few have retrofitted the diff to their cars on here (not just GT's). Also 1 or 2 on boards.ie
