Well, I guess I'll jump in...
I have used the Ikea wire hangers in both my
Scamp and recent
Perris Pacer resto. As advertised, these are tension wires, made taut by slick turnbuckle hardware. They do stick out further than I would prefer, but I like the look a lot.
The end "pins" that hold the curtain wire screw into a metal mounting plates. The plates fasten easily and firmly (with screws or bolts) to the upper cabinets (as you can see below), but are tricky to mount to the
fiberglass shell without the use of mechanical fasteners. I modified the mounting plates and used heavy duty resin epoxy to stick 'em directly to the FG walls.