So was the cell phone business before the iPhone and music player business before the iPod.
Not really. The iPod touch operated pretty much exactly the way an iPhone did, except calling. It almost seemed like a natural progression. I'm obviously well aware of the fact that it was a huge surprise seeing Apple enter that market, but the jump between what they use to do by going from sophisticated MP3/entertainment devices to one that actually could make a call, is still significantly smaller than what these rumours are. It would be a completely different market.
But cars are also changing rapidly and will probably be very different in terms of driving (semi/autonomous driving) and how most parts now are controlled by on-board computers, so maybe that's Apples angle.