Use of many WW2 and even older technologies. WW2 type vehicles, for instance, are easier to construct and maintain than many more modern machines which and thus would go better with DC Wastelands level of industry and technologies. This is especially true as various factions manufacture variations of basic WW2 machines.
Variations of some once common vehicles are returned in larger numbers
* Jeep (often with rollbars or rollcage)
* Beep (WW2 small truck used to carry troops etc.)
* Duece and a Half six wheeled truck
* Sherman Tank (improved)
* White halftrack truck
* Others?