Leading politicians expressed dismay at the fate of the domestic auto industry.

“Personally, I feel very sad, as we all do, for the end of an era,” Prime Minister Malcolm Turnbull said during a radio interview on Friday. He added that the majority of workers in Elizabeth had either found new employment, decided to go back to school or retired.

But union representatives said most of the laid-off workers will never get work in the manufacturing industry again.

The average length of service among those at the plant was about 20 years, according to the Australian Manufacturing Workers Union, and the average age of those affected by the closure was about 38.

But John Camillo, the union’s secretary in South Australia, said it was the workers over 50 that were particularly struggling to find new employment.

“It’s difficult out there, especially here in Adelaide,” Mr. Camillo said.

The decision to stop making cars in Australia reflects “the perfect storm of negative influences the car industry faces,” Mr. Turnbull said. He pointed to the continued strength of the Australian dollar, high production costs, and a small domestic market that is both competitive and fragmented.

The small size of the domestic car industry made it almost impossible to compete against foreign automakers.