[mattkevan]

It makes sense to own your own system, rather than rely on a third party whose interests may not remain aligned with yours. Remember the Google/Apple maps split.

Autonomous vehicles rely on extremely good mapping, and if the car companies don't own their own stack they are in danger of becoming mere OEMs, producing commodity hardware for someone else who extracts the value from the system. (It's debatable how well they will be able to execute, considering the quality of most in-car software.)

Also, in the short term I doubt that Google would licence maps for free.