Those are called Tonneau Flap Cables. They are not available to my knowledge, but some have been able to have replacements made at a bicycle shop.
There are several threads here that discuss them, most are not labeled correctly, either. Here is one:
https://www.crossfireforum.org/forum...cable-fix.html

If you are going to work on the car, download the service manual here:
https://www.crossfireforum.org/forum...ollection.html

I have moved your post to the Roadster forum, if you look in this part of the forum you will find most threads on the convertible top.