Not relevant. The software may not be patented but also just not published. You would have to reverse engineer it to get at the algorithms, and the car is surely heavily encrypted.
It's like Musk said with SpaceX: publishing patents is just like putting out a recipe book for China.
But not their "trade secrets". It's striking how little is publicly known about how each vendor's self-driving technology works. This is a technology that's grown up since the anti-patent "America Invents Act", and, as a result, there are few patents and much mystery. On rare occasions, someone gives a technical talk, but papers are seldom published.
It's like Musk said with SpaceX: publishing patents is just like putting out a recipe book for China.