I use a 5 foot length of 1/4" by 3" wide plexiglass between the mainsail and mast at the spreader bracket. It has four 1/2" holes drilled in it to allow heavy duty releasable cable ties to pass through and positively attach it. The foil still curves, but at a much larger radius that easily straightens after it's raised. I would suppose a piece of 3/8" or 1/2" plywood of the same dimensions would be flexible enough to serve the same duty, at reduced longevity.
I use an extended boat hook (something that's already on board) as a support for the overhang at the bow, and a boot (made from buoyancy compensator fabric, but a scrap of canvas would do) that snugly slides over the furler drum and line and overhanging part to hold it all together, and make it weather and (highway) windproof.
Originally I used the jib sheets spirally wrapped to hold the whole thing together, but don't like the time spent to spiral and unspiral it, and it takes time to loosen it for, say, storage; although it does look nice, and they're always there to use in a jiffy.
I also use various sail ties, and the ball-end bungee loops (they have faded a bit, but still holding up), but have discovered that more and more I am using the heavy duty trigger-releasable cable ties to supplant these, both for lashing the mainsail and mast, and for general boat duties. (Also used to secure the mast to the roller at the stern support).
They are instantly adjustable independently in both length and tightness (unlike bungees), fit in your pocket, can be connected to make them as long as needed (without concern about them coming apart), and are positive and solid in their holding power. You can loosen them enough during storage so they don't leave "bruises" in your sail, but still hold positive for trailering.
And practical for many other uses on-board, like securing fenders from bouncing over board. And maybe for handcuffing pirates.
OK, now back to our regularly-scheduled programming, the original thread topic... Maybe.
I have a '97 26X