The number of cars that the plant needed to produce within a month as part of the deal between management and the workers was 15,000. See more

Goofs

They need to make 15,000 cars in one month. It is never stated what month that is. However, they leave after 14,000 cars. But the next scene is shown at the July 4th Celebration. Unless they made 14,000 cars in 4 days, the plant would have been shut down by the 4th. See more