a 1965 Mustang
An appositive is a phrase that interrupts a sentence to clarify a noun. In this sentence, the appositive "a 1965 Mustang" is used to clarify the type of car or which car he is selling. We often use appositives to rename nouns. For example, My sister, Kate, is 3 years old. In this sentence the appositive clarifies which sister. An appositive phrase is always set off with commas. This is a great way to identify appositives because they are in the middle of commas.