Transit Connect - Insulation?

[Scifon]

Hey guys and girls, I'm looking to insulate my van as I've spent a few nights in it while working away to wake up to a free shower and condensation! I've bought 50mm celotex and a roll of ally bubble wrap but am not sure on what to do next. I plan to insulate the floor, ceiling and the spaces between the frames where there are bare pannels and then filling the voids with roof fibreglass that I was thinking of bagging and sealing.. Does this all sound sort of right? I've done a fair bit of research and there seems to be a lot of conflicting points.

I planned to stick the celotex straight onto the side pannels with a heavy duty adhesive or a spray glue but I've read that your should leave a gap for condensation to form and evaporate? Also when it comes to insulating over the corrugated roof what's the best method? Is it ok to place a sheet over the top or do I need to fill the valleys too?

Sorry for all the questions but I'm a bit out of my depth when it comes to this, thanks in advance people!

Here's what I'm working with, I've also put in a window in the roof so I have a source of ventilation.

[Scifon]

Sorry I can't work out how to rotate the images! :s

[ake]

Sorry I can't work out how to rotate the images! :s

It's ok they are the right way when you click on them