car maker vs auto manufacturer

car maker and auto manufacturer both are nouns.

Word	Noun	Adjective	Verb	Adverb
car maker	Yes	No	No	No
auto manufacturer	Yes	No	No	No

As nouns, car maker and auto manufacturer are synonyms defined as:

car maker and auto manufacturer: a business engaged in the manufacture of automobiles

Other synonyms of car maker include auto maker, automaker, car manufacturer, carmaker.

car maker (noun)	auto manufacturer (noun)
a business engaged in the manufacture of automobiles	a business engaged in the manufacture of automobiles