Rear disc Brakes on 8 3/4
got to figure that out with a BMW handle. I know you can adjust both single cables. And that makes totally sense. And you don't Need to cut a hole in the tunnel because of the spring which is in the handle.
here you can see where the cables are ending to the front. you Need to fab such a bracket.
this is the handle. You see that you have to cut a hole for the sheave with the cable into the tunnel. cable routs into the other direction off course
BMW handle Looks like this. BMW came first into my mind, i am open for other ideas but Ford I doesn't like. If you use the Ford e brake you also have to tension the spring first before the Brakes are engaging. If you wanna drift it is sub optimal :)
installed ( in a e30 BMW like a 325i ) it Looks like this. engaged. just needs a cover