I also can't see why the Car analogy is somehow invalid because cars only do one thing. For years having a car was essential for living in many (not all) modern cities, without a car you couldn't get to work, visit family or buy groceries. It was an essential tool for living in much the same way as computer will be in coming decades. People did not generally understand the inner workings of fuel injection, anti-lock brakes or catalytic converters, but that didn't mean engineers weren't able to introduce those things. They just had to articulate the performance/safety/economy/environmental benefits in terms that people understood and cared about. The same will be true for computers.