That would work on LHD cars Rene as I believe all later cars had the rear mounted battery feeding forward via two similar large gauge positive cables around 35mm2. The cables ran along the right hand side of car under door sill then upwards, one direct to starter motor and the other to battery positive distribution post behind that side of dash, close to glove box on LHD cars.
Assuming you have a later car, did you arrange for isolator to switch both feeds?
