The part-worn problem: where corners actually get cut
The used-tyre trade is where most of the genuine danger in this market lives. Part-worn tyres are sold cheaply from the back rows of industrial-area shops, often imported in bulk from markets where they were already retired. The problems stack: unknown history, possible internal damage from a previous impact, age often at or past the five-year threshold, and storage in shipping containers that bake in the sun for months. A tyre that spent a summer in an unventilated container has aged years in chemical terms. Municipal authorities have run repeated campaigns against non-compliant tyre stock, and this segment is the reason.
The corner-cutting is not always so blatant. It also looks like a shop fitting your tyre without checking the inside of the casing after a puncture, plugging a sidewall injury that legally and technically requires the tyre to be scrapped, or reusing a rusted valve stem to save five minutes. String plugs pushed in from the outside without demounting the tyre are a roadside expedient, acceptable to reach a workshop, not a permanent repair. A proper repair means demounting, inspecting the inner liner, and fitting a combination patch-plug from the inside, with the tyre rebalanced afterwards.