China is where the first fully autonomous cars will be sold
There will be a lot of regulatory and insurance hurdles in the US / Europe, so China is the place to be. In the meantime they can probably get access to the data the company has about where the drivers are taking people so they can improve Apple Maps data in China, and down the road they can instrument some of the private drivers' cars who volunteer with similar hardware to what Apple's car will use for sensors. Any time there is an accident or a close call, that data can be reviewed and the software Apple is working on tested to see how it would handle the situation, to insure that it handles all such situations as well as possible.