Nearly finished with finishing the interior of cab over portion. Still need to do the ceiling. To make the fabric covered p[anels, I used material from Perfect Fit and secured it to german Kapatech insulated panels. The Kapa stuff is thin aluminum over 3/8" foam. I secured 1/4" thick foam on the panel, then mated the fabric. The panels are snug fit but will get plastic push pins to secure. The end result here is a cozy sleep space that is super insulated and fully thermally broke. The gray plastic covers are actually electrical chases on both sides. The front covers snap on and off.