patrol car vs automobile

patrol car and automobile both are nouns.

Word	Noun	Adjective	Verb	Adverb
patrol car	Yes	No	No	No
automobile	Yes	No	Yes	No

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

patrol car: a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters
automobile: a motor vehicle with four wheels; usually propelled by an internal combustion engine

Other hypernyms of patrol car include auto, car, machine, motorcar.

patrol car (noun)	automobile (noun)
a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters	a motor vehicle with four wheels; usually propelled by an internal combustion engine

patrol car (verb)	automobile (verb)
	travel in an automobile