Hi, I have a 2004 1.2 Agila. It is used on the motorwayz couple of times a week. It doesn't have under bonnet sound deadening, and never did. Would buying after market sound deadening materially reduce sound in cabin from the engine, without causing engine over heating. The cooling system works OK. Also it has no ac, so in summer I will have to open windows. Will wind deflectors reduce wind noise, without affecting drag appreciably - its already like driving a wardrobe.