By "most basic", I mean cars that are cheap, if not the cheapest, to buy, own and repair, and are owned by people who can barely afford anything better than the bus, or don't wanna spend anything above the minimal amount on their car. In Puławy, Poland, such cars are Fiat Cinquecentos/Seicentos/Unos/early Puntos, 1.2-engined Renault Twingos, Mk1/2 Clios and Mk1 Kangoos, 1.0 Opel Corsa Bs, Daewoo Matizes, VW Polo Mk2s and Peugeot 106s/206s (base engines). And what about your area?
Good news! Its the dacia sandero! In other words my neighbour has 2 of them so he has one car to drive to work as everyday one wont work
In Kragujevac usually a Fiat Punto II, Fiat Seicento, Dacia Logan I, Yugo Koral, Renault Clio II Phase II or Peugeot 206.
(Can I mention cars that are used by services?) My city's taxi service only use Priuses and Malibus/Impalas, which I'm sure aren't that expensive, considering all of them are around the early to mid 2000s. Also, Corollas, Camries, Impalas, Malibus, and F-Series for civilians are usually dozens in my city.