This is the 9860th most frequent Russian word.
автомобильное
"Автомобильное" means "automobile-related" or "pertaining to cars."
Here, 'автомобильное' is used as an adjective describing 'зеркало', indicating that the mirror is related to an automobile.
Автомобильное зеркало важно для обеспечения безопасности на дороге.
The automobile mirror is important for ensuring safety on the road.
In this sentence, 'автомобильной' is in the feminine form, agreeing with 'промышленности', and is used to specify the type of industry as related to automobiles.
Мой друг работает в автомобильной промышленности.
My friend works in the automobile industry.
Here, 'автомобильного' is in the neuter form to match 'использования', denoting that the usage pertains to automobiles.