Sorting is one thing that can be done explicitly by one or more fields.
But this issues is about computing the score of a document based on various parameters including word frequency and in this case distance. The list is ordered by the score.

For example a car matching perfectly but at 3 km might show up first because the weight of color / brand etc is higher than the weight of distance.
Then a partially matching car a 1 km can show up second

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