For car shootings, they had to collect manually a metal design which was fastened to the car in front. The operator sat in a luggage carrier going ahead of the car. And in other shots, movie cameras were fixed on the long piece of wood lying about a windshield. Often they could look at a shot only after all cars will stop therefore actors had to repeat scenes in the car many times, constantly improvising.
They completely built house on the field middle. All film crew had to study bases of construction and painting of materials. There were ideas to construct it of a metal framework, for convenience, but nevertheless they chose wooden materials because the design of them was easier in this case.
Thinking out the building concept, they drew it chalk on asphalt and played scenes in the drawn house.
For all difficult special effects it was necessary to build various improbable designs. Because of the squeezed schedule, often it was necessary to build at night and to sleep directly in the field.
In the conditions of the limited budget film crew weren't able to afford expensive film-making equipment therefore it was necessary to invent a lot of things.