I would ask for a reputable Breaker in the area or DYI with adequate cross section wires.
We have them wires shared in most of the cases with color codes and cross sections, but some soldering iron skills would be needed. Plus some materials.
Some wires here:
Parts catalogs. Spare parts catalog Mercedes EPC Online. Mercedes. Car. ELECTRICAL EQUIPMENT AND INSTRUMENTS.
nemigaparts.com
Not sure if you gonna find separate cable or not, but
with a part number (depending the length, designation, etc.) is easier!