I have been driving the Defender for a couple of months now with the metal roof (and various wires) exposed – the original internal ceiling was fairly worn and discoloured, ripe for renewal. But first, with winter approaching, it seemed to us to be a good idea to insulate the roof. This stuff – foam backed on one side by foil and on the other by self-adhesive tape – seemed to fit the bill. A few hours later and it was all done, ready for the installation of the headliner.