estate car vs auto

estate car and auto both are nouns.

Word	Noun	Adjective	Verb	Adverb
estate car	Yes	No	No	No
auto	Yes	No	No	No

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

estate car: a car that has a long body and rear door with space behind rear seat
auto: a motor vehicle with four wheels; usually propelled by an internal combustion engine

Other hypernyms of estate car include automobile, car, machine, motorcar.

estate car (noun)	auto (noun)
a car that has a long body and rear door with space behind rear seat	a motor vehicle with four wheels; usually propelled by an internal combustion engine