Nice, you’ll sell the wished cable.
Unfortunately, for the moment you give us no solution to solve it, to build it, to buy it…
I’m lucky, on my side it’s solved here, your other customers are not so lucky and they don’t laugh…
https://www.cdiscount.com/informatique/cables-connectiques/adaptateur-cable-sata-vers-4-pins-alimentation-car/f-1072003-auc2008433180359.html
How build this cable ourselves ? it’s easy, I agree, but where can we find the needed parts ?