The court has heard testimony from dozens of people including Pedro Troiani and Carlos Propato, who were trade union leaders at Ford in Argentina when they were detained in the factory and tortured by the military dictatorship.
They were held prisoner for two years and letters were sent to their families claiming they had been fired for failing to show up for work.
Also on trial is former general Santiago Riveros, who headed a secret detention centre called Campo de Mayo where the men were held. He has previously been convicted of crimes against humanity.
Complaints have been made against other international auto-makers, including Mercedes Benz, Renault and Fiat, but only the Ford case has so far gone to trial.
"We hope that there is a verdict of responsibility, so that it is settled that there was a complicity between business and the dictatorship, which is very important for the history of Argentina," victims' lawyer Tomas Ojea told AFP.
It's the first time that executives of a multinational company have been put on trial for crimes committed during the dictatorship.
The company itself is not implicated, but prosecutors are seeking to demonstrate there was complicity with the dictatorship responsible for the deaths and disappearances of some 30,000 people, according to human rights organizations.
"The obstacles to prosecuting businessmen complicit in human rights abuses are enormous in Argentina and the world in general. Hence the importance of this process, and fortunately we have reached the end this year," said Ojea.
"There are certain legal obstacles to taking civil suits, which have to do with the statute of limitations, so if we had brought a case against Ford itself as a company, our assessment was that the trial would not have advanced as it has," said Ojea.
When the military took over in a 1976 coup d'etat, some 5,000 workers were employed at the plant, as well as 2,500 administrative staff.