squad car vs patrol car

squad car and patrol car both are nouns.

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

As nouns, squad car and patrol car are synonyms defined as:

squad car and patrol car: a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters

Other synonyms of squad car include cruiser, police car, police cruiser, prowl car.

squad car (noun)	patrol car (noun)
a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters	a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters