When I did the ceiling in my previous van, I used that white paneling you find in RVs and Home Depot (and others) and I fastened them to strips of 1/2" plywood screwed to the steel frame:
I then used these plastic caps so I couldn't see the hardware but still access them if needed:
It's not exactly a blind connection but close.
I also used a fair amount of Loctite PL adhesive
. Of course, I had to be sure I would not comeback on my decision.