automaker vs auto maker

automaker and auto maker both are nouns.

Word	Noun	Adjective	Verb	Adverb
automaker	Yes	No	No	No
auto maker	Yes	No	No	No

As nouns, automaker and auto maker are synonyms defined as:

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

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

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