In the battle to define the autonomous car, established automakers such as Mercedes-Benz and newcomers such as Google are slugging it out in labs and on the road.

It's a big deal. Those that prevail will be in pole position for what Boston Consulting Group sees as a $42 billion revenue stream by 2025. And that's just when the sector starts to hit its stride. The victors will help shape the future of personal transportation.

So which business model will win? Will it be the traditional auto industry, building on a century of continually refining conventional vehicles? Or innovative Silicon Valley companies starting a new business model from a clean sheet of paper? Or perhaps a combination of both, alternately collaborating and competing with each other?

Creating vehicles that are fully autonomous will be a complicated process. It starts with developing and integrating dozens of new technologies and devices. The industry must create standards so different self-driving vehicles can communicate with one another to ensure safety.

Legislators must still figure out how to regulate the emerging sector. Based on experience with previous new technologies, Boston Consulting expects that legislation alone will take several years.

Finally, participants must create profitable business plans.

It's unclear whether autonomous vehicles will fit within the prevailing model of private ownership or encourage shared ownership. Multiple solutions are possible, even likely.

But the auto industry was formed by competition. However the struggle is resolved, the automobile, and by extension the industry, will be better because of it.