Another major factor is the trillions tied up in automated machine tooling not only to produce car engines but any ic engine, just look at all the cheap generators, chainsaws and weed whackers you can buy now, they're moulding them out like sweeties with minimal machining. Compared to the old Henry Ford engine productions lines there's not a person in sight its all done by computer from casting to final assembly it a bit like comparing vinyl to cd.