Once upon a time, in a hobby shop far, far away, we used to be able to buy from "Auto World" this stuff they called "Plas-T-Rod".
It was dark grey in color, smooth, stiff but bendable without breaking (like styrene breaks) and was perfect for roll bars and entire roll cages.
Without resorting to solder wire, what are we using today, and better yet, what was that Plas-T-Rod stuff anyway and can we get more?