Reflooring the van

[iplayguitarintheshower]

Hey All

So im tearing out the old carpet in my conversion van. 94 GMC Vandura 2500. The installer, whomever it was, did a half assed job. The window sills are held up with pieces of 2x4 snugged up against the body panels and insulation. its a fucking joke.

Anyway, I got the walling removed (mostly felt on plywood) to get at the carpet and underlayment polyiso boards. I dont see any sign of actual plywood...The carpet was on top a 1/8'' foam which sat on top of the 1/2 '' polyiso boarding then the sheet metal below it.

I'm going to rip out the existing polyiso boarding as its half stuck with carpet backing and 1/8'' in foaming. Going to install vinyl peel n stick flooring.

MY QUESTION!

What should the order be for new flooring? I'm guessing..

1. van body 
2. Insulation inbetween the body ribs to even out the surface 
3. Foam backed reflective heat/sound insulation (shiny side up) 
4. Underlayment (either void free osb plywood, luna, or perhaps the polyiso board)
5. Vinyl Planks

Is this correct? Whos done flooring before on a van and can weigh in on this?