The only piece I removed was the side step. I took a flat blade and just pried up about every 15 cm until all the plastic snaps had popped out. The side step does go underneath the side panel, but once all the steps plastic snaps are undone it has enough movement that you can maneuver it out from underneath the side panel. FYI, in mine the side panel is put on with some annoying "permanent" plastic snaps, where as the step is put on with a removable style. Next step will probably just be to put the step back for now. I don't think that I have the time this year to make a pretty storage solution, I just wanted to see what I was up against. Once I do get more time I might try drilling out the spot welds to release the panel and tap in to all that hidden space!
No carpet in mine, front is all rubber liner. The liner goes under the seat and then forms a lip at the front of that rectangular tube in the floor panel assembly.