I cut the Velcro strips in three pieces and glued the pieces of the first strip to the back of the boot cover, and those of the second strip to the flat side of the curtain rod. When in use, the curtain rod attaches with the Velcro to the boot cover about 1/2 inch above the stitched seam, and is held in place below the outmost braces of the metal frame of the soft top.
I did some careful measuring before glueing anything to the boot cover and ended up with a distance between the stitches and the closest edge of the center Velcro piece equal to about 1/2 inch. The Velcro pieces at the ends were 1/2 inch away from the stitches at their outmost points, and 1/4 inch at their innermost points. These numbers might not be best for you. Try with the boot cover on the car. I covered the ends of the curtain rod with tape to prevent scratches and noise.
I made a mark on the pieces of curtain rod to indicate the correct 43 inch length of the rod when installed. I bend the end of the inner curtain rod piece outward a bit with a screw driver so that it does not slide too easily within the other piece but stays at the right length.
Other 1996 owners have complained that their boot cover often comes loose at some point of the edge. Mine usually does not as long as I put it on very carefully: buttons first, then foremost edges around the lip on the car, followed by the rest of the boot's rear edge. The boot stiffener does not seem to help, actually it seems more likely for a part of the boot edge to come loose with it on. (Somewhat harder to get it precisely centered on the velcro.) However, I have recently learned that other people, after putting on the boot, work the foremost ends forward to tension the edge. Since my boot usually stays put anyway, I am not sure whether this works better, but it does makes sense.
A minor annoyance is that the Velcro strips on the curtain rods stick to the carpeting of the trunk. If I had to do it over, I would put the Velcro loops on the rod and the hooks on the boot cover.
I used very thin plastic tape on the ends of the curtain rod, and I can occasionally hear them ticking against the metal frame. So I plan to put electrical tape or felt on the ends instead sometime.
I bent one of the curtain rods by accident, they are not very strong. Since the rod is invisible when installed, I simply bent it back straight again.
After use, some of the corners of the velcro strips on the boot cover have come loose, and those of the velcro strips on the curtain rod even more. (Actually, unlike the velcro strips on the boot, the velcro strips on the rod have a sticky back and were stuck on instead of glued on - I wasted the glue-on strips on an earlier failed attempt. Next time I will use glued strips on the rod also.) For now I simply push the corners back on the rod.
Despite these minor deficiencies. I am very pleased with the stiffener and use it all the time.
Boot cover with the three Velcro strips at the right.
Boot cover attached to the curtain rod.
After closing the boot cover.