A.K.A.-47: Several of the cars are recognizable as real-world ones, sans real names. Among them are a Mini Cooper, a 70's era Firebird and an El Camino- amusingly named the Cajones.
Alternate History: The story starts with a massive plague striking humanity in the 1980s.
Amusement Park of Doom: Well, it's more of a carnival of drugs and prostitutes and the clowns are more darkly hilarious then intimidating, but hey, people get killed often. Visually, the Daredevils' carnival hangout fits the trope, including the gigantic Sweet Tooth-esque clown face.
Football Hooligans: The South League gang in Paradise City. They're a rowdy bunch who apply a football metaphor to everything from parties to fighting the Sentinels and the Dregs for control of the city. They're also the most sympathetic of the gangs Mason allies with.
The Remnant: The Section 8s gang of Blister Canyon appear to be the vestiges of the US military. However, they soon appear to be a bit... well, flowery.
Sequel Hook: In the ending, Mason receives a radio transmission from a settlement somewhere out in the wastes that is under attack. He decides to go help, saying something like "Here we go again."
Sidekick: A Daredevils guy (who happens to not be a clown or English-sounding) joins Mason at the beginning of the game, manning the turret gun of his cars, ostensibly to keep an eye on him for the Daredevils boss. By the end of the game, the two are Fire-Forged Friends.
Witty Banter: Aside from the main characters themselves, the radio show personalities are really funny to listen to, especially the two hosts of WYLD 66.6 interviewing The Fuzz Brothers, The gravely-voiced Thunder Bob, host of the classic rock station, and the two midwestern-sounding guys who host a talk show about cars and weapons.
Wretched Hive: All three cities. Lava Falls and Blister Canyon are pretty overt about it, whereas Paradise City has a thin veil of order maintained by the Sentinels' Police Brutality. The people there do have a somewhat better standard of living then the other areas. Regardless, it's largely Played for Laughs.