car manufacturer vs carmaker

car manufacturer and carmaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
car manufacturer	Yes	No	No	No
carmaker	Yes	No	No	No

As nouns, car manufacturer and carmaker are synonyms defined as:

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

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

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