must be a hatch.... duh
remove the hatch
add a support bar to each C-pillar
(notice the signal s13 has a cage0
they fabbed a wall of sheet metal and connected the lower section to the floor- then - to the support bar.
lexan window in a fabbed frame connects
to the roof and the support bar.
a piece is added to the connnecting spots
and secures them together.
you might want to see some detailed pictures of the S13-truck
because it takes work to set it off . the Signal truck isn't intended on being a show piece so they whipped it up .
also remember they use that truck at events to move rims and body parts ect .
It would be awesome if you pulled it off !!
let me know if you figured a way to do the coupe~lol