Dodo matt thermo fleece is the final stage of your insulation process and this mainly covers the areas that are recessed like the doors and walls and the ceiling . This can be pushed into any voids but be careful not to pull any wires when doing so as you won’t realise until something doesn’t work so take care . You can easily cut this with a sharp pair of scissors . This isn’t self adhesive so buy some spray adhesive used for sticking carpet down  and spray the wall and one side of the insulation and wait until touch dry then stick in place . Once this is installed that’s it ! your done with insulating and using all three stages you have done the best job possible . Oh don’t forget to remove the factory cab head liner and repeat all three stages as that will condensate and cause problems further down the line .