Opel annual sales in 2019 was 800k, half their peak of 1.6 million in 1999 and there sales graph is basically a steady continuous drop in that period: https://carsalesbase.com/europe-opel-vauxhall/

The people who historically would have bought Opels or Vauxhalls (thanks to high numbers of UK imports, you used to see both here) now tend to buy Toyotas and Kias mostly today, at least in my country.