Yes you are supposed to take a slight pause after saying the phrase "As Previously mentioned"
C.writing immortal poetry
The two words Bradbury uses repeatedly in this scene are "The beetle". The repetition adds to the suspense of the scene. Each time "the beetle" is repeated the reader can feel the car getting closer and closer. Because the sentences are very short and similarly structured, they speed up the pace of the scene just like the car is picking up speed.
