nonsmoker vs passenger car

nonsmoker and passenger car both are nouns.

Word	Noun	Adjective	Verb	Adverb
nonsmoker	Yes	No	No	No
passenger car	Yes	No	No	No

As nouns, passenger car is a hypernym of nonsmoker; that is, passenger car is a word with a broader meaning than nonsmoker:

Other hypernyms of nonsmoker include carriage, coach.

nonsmoker (noun)	passenger car (noun)
a passenger car for passengers who want to avoid tobacco smoke	a railcar where passengers ride
a person who does not smoke tobacco