plywood flooring MPV - query

Planning on ply lining my MPV floor as part of a rudimentary camper conversion. Can i ask anyone who has done this how they went about it, specifically with regard to levelling the floor prior to laying the ply.

My plan was to put down thin timber battens (18 x 10.5mm) glued or siliconed to the floor, followed by a layer of foil/bubble insulation , then just lay the 9mm ply floating rather than securing it (I'd like to be able to remove the front section at will to put the front passenger seats in). It'll be in two parts.

My problem is that the peaks and troughs in the floor dont seem to be even/consistent. On top of which some bits have factory fitted insulation but not all. Do I need to lay different thickness battens? Is the difference too small to matter? Do I want all battens to stand proud of the floor ridges (is a raised floor) or do I want things as level as possibleto them original van floor. Argh!

In short, any tips from anyone who has done this would be very welcome.

On a separate note... Why is timber never properly straight!!

38x19mm battens (el cheapo B&Q crap) bonded to the floor between the strengthening ribs. Foil/bubblewrap insulation cut and laid between - 2 layers, then 9mm ply screwed to the battens. Quick and easy.

Brilliant! Thanks for your speedy response. I think it might have been your photo I was trying to find (without success) as I knew I'd seen a phota and explanation somewhere.

So your floor is quite raised, but effectively just sits on 6 or 7 spaced out battens, rather than trying get a uniform level everywhere? If so that will save me a ton of wood and heartache!

Out of interest, what did you do for battery access and for the edging?

It isn't raised a great deal, the battens stand proud about 10mm and the ply is 9mm so about 2cms in total. The battery access is staying as in the pic - I've bodged made some removeable built in units to act as seating/storage with encloses the battery cover. In time (ie, when I pull my digit out) I'll be placing a leisure battery in a removeable box on top of the engine battery cover and inside the seating units.

Edging, when I get a round toit, will be a length of wood batten under the ply to provide suport and finished with a rounded edged ali strip.