system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 - How are "Pirate" car parts made?

I recently purchased some DEPO branded headlights for my car, because I was planning to cut them up to retrofit projectors.

Upon inspection I noticed that each component of the assembly was almost OEM apart from a few areas where plastic seemed to “leak” out of the mould.

I  was curious as to how they are manufactured to the same shape and specifications as OEM if they had to use their own production techniques. Are these parts just manufactured using old OEM molds and dies?
gpt
A decent amount of the time they're made on the same molds and dies as the OEM parts. Some factory in China takes an order for 20,000 headlights from Ford, makes the tooling, makes the order, then files off the logos on the mold and runs off another 50,000 until the mold wears out.

Most of the big OEMs aren't really interested in pursuing that sort of thing because it's just seen as the cost of doing business in China.