Okay. I did this on a Mk3. Couldn't find one of the little joiner blocks, but improvised after I broke the bent hook end off the original rod :/
Anyway, my question is, if I did it the long way, running a wire to the front of the car (which took aaages), which of the 3 wires to the wiper motor should I use as a ground. I tried connecting to the plate that holds it, but I only get ground when the boot is open for some reason