This is the 4263rd most frequent Russian word.
автомобильный
Automobile-related.
The adjective "автомобильный" is used to describe something related to an automobile, in this case, the motor.
Автомобильный мотор требует регулярного обслуживания.
The automobile engine requires regular maintenance.
Here, "автомобильный" characterizes the museum as being focused on automobiles.
Мы посетили автомобильный музей в Москве.
We visited an automobile museum in Moscow.
In this usage, "автомобильный" modifies the navigator, indicating it is designed specifically for use in automobiles.