Interior advice

[JustinFBird]

Like the tittle says I’m looking for some advice. I’m currently working on my interior and want to lay down some membrane. The car needs to be painted, probably taken down to bare metal so probably sandblasting or something along the lines. I don’t plan on doing paint for awhile (years) I want to enjoy it. Would it be a bad idea to lay down some membrane down before doing that ? I’ve replaced all floor pans that have had damage, subframe connectors are already welded in. I have a restomod air unit sitting in box, trying to make the most out of it.