Insulation in walls

I bought some rock wool from B&Q (£20 a roll) and thick gauge plastic (£20) to use as a vapour barrier. I had already painted the entire van in Thompsons Roof Seal to prevent rust if I got my kayak stuff in there.

It was simple enough to install but takes time. I had looked at other options but most were too expensive or unavailable at the time. B&Q sold some lovely silver bubble wrap stuff that I would have possibly used instead if it wasn't £30 a roll and I needed two of them.