The traffic sign in the credits says something different in each episode. Episode 1: "The End of the street is nigh." Episode 2: "You may now Text and Drive." Episode 3: "Road paved with shoddy intentions." Episode 4: "Tailgate Not Lest Ye Be Tailgated."
The movie playing in the theater during the opening credits is different in each episode: Episode 1: The Core. Episode 2: Pluto Nash. Episode 3: "Legend of the Guardians the owls of Gahoole." Episode 4: "Grave of the Fireflies."