Made it through the thread!
Here are my notes on a super simple box foamie:
Foamie Build
Super Simple Box, 48x96x48
Old boat trailer, 48" wide frame area
Cut 2” foam panels to size (2 – 44x48 (front, rear), 3 – 48x96 (sides and roof))
Apply kraft paper over TB III, both sides of foam to all foam parts
Make floor using 1x2 frame, openings filled with 3/4” foam, skinned with 5mm underlayment top and bottom
Glue sides, front and rear panels to floor and each other with Gorilla Glue
Glue roof to walls with Gorilla Glue
Round all corners a bit
Glue Fiberglass Drywall Tape to all corners, seams and joins inside and out with TB III
Cover FDT with kraft paper and TB III
Paint with exterior acrylic latex paint
Cut in door in rear, sailboat washboards with hatch on top? Or side door with canvas hinge?
Cut in and build 2 dorade vents
Cut a few small windows on sides, rabbet, glue in plexiglass
Drop onto trailer, bolt down
I still need to work out a cheap and simple door.
I am not sure I will build this, because I am getting ideas how to make a more aerodynamic version. I need to wait till spring anyway, so I have some time to design.