I ran mine from starter through a geometry in the steering wheel rack rubber to a kill switch above the shifter. Then from there under passenger front seat and to the rear seat and then along body wheel arch through boot to Batt box. I used conduit to reduce chance of arcing if cable wire through in 200years . Formed conduit to body shape by heating over camp burner and holding it to the car. Then fed cable trough once formed.

with battery re-located to the tray, where did you guys run the cable's