Interesting timing on this thread, i've spent the last week removing headliners and insulating and adding a second skylight in the rear. Here's my
I'm stuffing the hollow body panels with 1" foam rubber, like used for chair and bed padding. It's super easy to work with and fills cavities with a very dense material. Over the top (or under, on the roof) of this goes a layer of reflectix. That is attached to the back of the side panel with enough tape to keep it from moving. When the panels are put back on, the reflectix seals it nice and tight.
The stuffing in the ceiling was tricky to hold in place, ended up using 1/4" dowells stuck under the ribs. Would rather it fall down to the headliner and not stay compressed to the metal.
The sunroof will be nice addition in the summer. Removed one cross rib, and i'm thinking i'll put some 3/4" sq. tubing alongside to reinforce it.
Got this thing in January, feels good to FINALLY get going on building it.
Jef