I spent a little time writing software for a plastic injection moulding company who supplied parts for a range of different automotive suppliers.

You could say that they were all made the same way — they were all moulded from tiny little plastic balls that are melted down — but the reality is that there was a huge difference in the products produced for each vehicle.

The vent for an A/C is one example. To produce that piece for a Ford might be one piece of plastic, which falls off the conveyor at about 1 every 20 seconds. The same piece for an Audi would take 3 different types of plastic, and some rubbery material, and would take about two minutes per unit - as well as some assembly, by a human, before it is done.