In linguistics, predicate transfer is the reassignment of a property to an object which would not otherwise inherently have that property. Thus, the expression "I am parked out back" conveys the meaning of "parked" from "car" to the property of "I possess a car". This avoids incorrect polysemous

Polysemy

Polysemy is the capacity for a sign or signs to have multiple meanings , i.e., a large semantic field.Charles Fillmore and Beryl Atkins’ definition stipulates three elements: the various senses of a polysemous word have a central origin, the links between these senses form a network, and ...

 interpretations of "parked": that "people can be parked", or that "I am pretending to be a car", or that "I am something which can be parked". This is supported by the morphology

Morphology (linguistics)

In linguistics, morphology is the identification, analysis and description, in a language, of the structure of morphemes and other linguistic units, such as words, affixes, parts of speech, intonation/stress, or implied context...

: "We are parked out back" does not mean that there are multiple cars; rather, that there are multiple passengers (having the property of being in possession of a car).