Answer:
The answer to your question would be that the intransitive verb in the sentence is "sat".
Step-by-step explanation:
Intransitive verbs are generally action verbs, expressing a doable activity, such as sneeze, run, arrive. They select only one argument which functions as the subject. In the sentence above, the intransitive verb to sit selects only one argument, the noun phrase I. The prepositional phrase "in the passenger seat" is a modifier of place indicating location.