I guess they buy those speakers by the boat load for pennies, and three rivets takes seconds to fit.
Going by all the stickers inside the door, and name pressed in to the metal, they are designed/manufactured by a sub-contract specialist firm.
No different to Bosch, Recaro, Hella etc.
Cars are just business, and not a very profitable one these days.
Still, it keeps us amused putting all these things right!