I used to own a troopy and back then had a Hifly 265. Travelling north and south i strapped all my gear to the ceiling inside. Screwed some buckles to each side above the windows where the roof braces are and in the centre of the braces. using board tiedowns i looped through the buckles and slipped the board, mast, sails and boom and pulled them tight. Nice and secure, plenty of room to sleep and all your other gear under your bed. I don't have any photos unfortunately.
It was a good set up. If you looked in through the window you couldn't see the gear strapped to the ceiling unless you looked up. Most people look down when they look inside a car

I miss my troopy