I went through the wheel wells and ran them in concert with the existing harness cabling. They are pretty invisible . My control box is fixed under the back of the center console , behind the ashtray position. I did try other potential runs but always was slightly short with the specialist cable length supplied , so that was the only realistic option for me.
If I was to do it again I would buy an additional 3m of cable and mount the controller in the front boot, and run the cable through the door sills. The controller would be more accessible and would not be exposed to accidental boots and knees doing any front engine work when required.