GM is getting ready to deploy self driving cars on a ride sharing business model. This seems like a far better way to initially deploy and develop self driving cars, where GM can far more easily work with cars they control, than cars sold to the public. This also allows them to continuously use best of breed, rather than be tied to a single system or platform. This seems a far better way to develop a system. than combine two companies, neither of which makes cars. This is a far more efficient use of resources and talent with for more flexibility to adapt to the "Great Acceleration" we are now living in. It's far better to use strategy than just throw money and resources at a challenge.
Cars are a complete system and this allows GM to develop and test a wider variety of technologies and platforms, than just creating an add on system developed in isolation. Autos already have extensive computer systems and to not fully integrate these from the start needs a single unified strategy that this model provides. Link below.