Good smartphones (with capacitive touch-screens, and webkit-based browsers) are also revolutionary. But there's only two companies making much money out of them, and only one of them has been in the phone industry for long (and even Samsung was never that great at phones).

Cars don't just sell a way to get from point A to point B. They sell an experience. If that experience becomes "put your destination into your GPS, then play Angry Birds for a while", then it will turn the car itself into a commodity.