So, my speedometer cable broke again and there aren't any MX-3's left in the junkyards near me. Looked for 90's Protege's even Escorts, Tracers, 323's but nothing. I ran out ov ideas for interchangeable parts and just went to Mazda. I only broke the lower cable so I tried to be cheap and order only that one part.
Today I picked up my new lower speed cable and it no longer has the plastic connector, mid cable. It's all metal. Kinda looks like a garden hose connection. I don't think the plastic can be connected to the metal, so I had to order the top half as well. In total about $100 for both.
The moral ov the story; If you are going to replace your speed cable you need the WHOLE updated cable assembly. I guess you could use the old dust boot (I won't know for sure until the part comes in tomorrow).
On the + side, I probably won't have to replace my speedo cable again, EVER.
And, I shouldn't have to worry about it going crazy when it's cold out because the Protege cable isn't sitting right. 
GOOD LUCK to all. Happy MX-ing.
I'm going to try again
But it's kinda like a medicine bottle, push and twist. 