patrol wagon vs police van

patrol wagon and police van both are nouns.

Word	Noun	Adjective	Verb	Adverb
patrol wagon	Yes	No	No	No
police van	Yes	No	No	No

As nouns, patrol wagon and police van are synonyms defined as:

Other synonyms of patrol wagon include black Maria, paddy wagon, police wagon, wagon.

patrol wagon (noun)	police van (noun)
van used by police to transport prisoners	van used by police to transport prisoners