similar thing but far far cheaper would be to get a breathable ground sheet, but you could also use the 60cm squared foam flooring that fits together in a jigsaw type of way, again very much cheaper and would give you good insulation too
The link didn't work because they are closed until Tuesday!
I can't help thinking that adding insulation and promoting air circulation are contradictory goals.
We've always had slatted bases in our trailer tents, and never had problems. On Camplets they are an extra, and sometimes people just go to Ikea instead because it's cheaper. However, if you add anything that deep to a folding camper bed, you would have to remove it to fold the unit up. Also, the Pennines don't have a particularly big payload, so weight is a consideration and slats tend to be heavy.
I might have a different opinion when we've used our Countryman a few more times though!
Condensation normally collects on the coldest surfaces, so the trick is to make sure things don't get cold. As long as you've got somewhere for the moist air to escape, you should be ok.
I've got a 2003 model, which has plywood beds - not sure if this would be suitable for more recent models, but I've put down 3mm foam reflector foil on the inside (stapled / taped down with aluminium tape). I've also painted the underside black on the outside.
I also replaced the old sprung matresses with memory foam matresses, which are significantly lighter.
I've not had any problems with condensation, however I don't tend to zip up the bed pods.
I've currently got Sunncamp 2-birth inner tents in the bed pods, rather than the Pennine cotton ones, as the old Pennine ones had mildew on them.
Being polyester, if anything I'd expect to have more condensation with these inner tents, but they seem to be fine... and they do have the advantage of being waterproof for setting up/packing away in the rain.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.