Hi all ,new member here ,couple of questions first my Aircon has stopped working,I bought car back in Feb from dealer in Stockport had issue with adblue tank going home ,(live up in Scotland) got fixed under warranty and got Aircon regass as well ,was working now not light stays on whereas before didn't,any ideas ?also being the permanent quattro looking to change the diff oil anyone know what spec it is and how much I will need thanks