What I've learned sourcing aftermarket parts for Isuzu trucks

I work in the automotive aftermarket in China, mainly around Japanese pickups and light commercial vehicles.

One thing I've learned is that sourcing parts for vehicles like the D-MAX, NPR and NKR is often more complicated than simply finding a supplier.

A customer may give you a photo or an OE number, but you still need to confirm the exact application, model, engine, year and market.

The other challenge is finding a supplier that can consistently reproduce the same specification rather than just providing a good sample once.

For people here who work on or maintain Isuzu vehicles professionally:

What is usually the biggest headache when sourcing aftermarket parts — identifying the correct part, finding a reliable supplier, or getting consistent quality?