From The McGraw-Hill Handbook of English grammar and usage, 320p
Adjective prepositional phrases are prepositional phrases functioning as adjectives to modify nouns. For example, in the sentence The car in the driveway belongs to my aunt, the adjective prepositional phrase in the driveway modifies the noun car.
In the NP, "in the driveway" modifies the "the car". Like the preceding, in a structure level The car is in the driveway, can we say that the prepositional phrase "in the driveway" moidifies "the car", or does it modify a linking verb "is"?