When I bought our roadster ten years ago both trunk bracket dividers were broken. It was easy enough and cheap enough to find them on Ebay at the time so I order two with the switches for the left side and one without the switch for the right side. The most common failure of this part is the plastic tab that holds the trunk divider's rod in place. Improper removal and fatigue of the thin plastic tab is likely why this has been a common failure for some roadsters.
The other day (ten years later) after considering a couple of potentially unsuccessful solutions I came up with a fix that should work, costs pennies, and should hold up over time. The photo below show that I cut a piece of 3/16 inch ABS plastic sheet in 7/8th"wide X 3 1/2" long strips. I used a 2"X4" piece of scrap wood and cut the profile of the bracket that I had traced on a piece of paper. I then heated the ABS strip to the point of being extremely flexible (like a well done wet noddle) and then clamped it in my homemade jig until it cooled.
The bracket and strip were then scuffed and JB Weld "Plastic Bonder" High Strength Structural Adhesive was applied.

 

A closer look.

 

Nice.

 

Thank you. Sometimes the most effective and easiest solutions are the hardest for me to figure out.

 

You could probably sell those parts?

 

I think that the surfaces that are bonded together should be as long and as wide as possible to get the maximum strength.

 

I couldn't agree more. I tested the adhesion by ruffing the surface of two pieces of plastic and wiping with isopropal alcohol prior to application and the bond did not fail. The ABS which is pretty strong stuff eventually failed from me continually trying to flex it "180" degrees multiple times trying to break the two test pieces apart. I'm pretty confident that it would take some type of catastrophic event for it to fail.
Below is a photo of a non-broken trunk divider that is reinforced with the ABS plastic to give it additional strength.
If one has reasonable skills this is pretty easy to do. The cost of the plastic is probably less the two bits. And if you went to your local plastic store and asked them for the size of pieces I have previously indicated they'd probably just laugh and give you a scrap piece for free. Purchasing the glue would be your only expense (about $6.00).

 

Acetone is an excellent adhesive, it literally turns the surface into a liquid state, two coats of it on each face and whenpressed together they become united. Practice on some scraps first to get the feel for it and then test the bond.

 

Unfortunately the Trunk Bracket Divider is not made of ABS plastic and acetone has no effect on the type of plastic it is made from.