Walt Mossberg:

Silicon Valley is forcing its way onto Detroit’s turf by building, or planning to build, cars. And that means there could be some big clashes, or at least some tense partnerships, in coming years. The big automakers are all seeking to learn from, and hire from, the tech industry. Some joint efforts are happening or being discussed. But, privately, at least some of the car companies worry that they may face wealthy, smart new competitors.
 You don’t have to wait for the future to get a taste of this. A small version of the coming changes — part partnership, part tension — is already playing out, right now, in car dealerships across the country. It’s the question of who controls the dashboard, or at least that big center screen in the middle of it.