Lets face it cars per se are a diminishing part of the market these days. By far the most successful Ford is the Ranger (second most popular in sales terms overall, behind the HiLux. SUV (small medium and large) and Ute sales account for far more units sold from all manufacturers, more than total passenger cars of all sizes.. The best selling vehicle in Australia is I believe the Toyota HiLux. Ford are hardly a major player these days, having fallen behind Mitsubishi in total unit sales.
It is hard for Ford or Holden to justify spending money on Supercars as the passenger car market continues to diminish.
A breakdown of 2017 sales can be found here:
https://www.drive.com.au/motor-news/...evealed-116814