except Uber already has a partnership with Volvo

http://www.theverge.com/2016/8/18/12541672/uber-volvo-partne...

Investment from Toyota

https://techcrunch.com/2016/05/24/uber-and-toyota-confirm-st...

and they can retrofit existing cars with their autonomous technology which they are doing today/planning to do in the future, they aren't using any of the autonomous technology created by the manufacturers with no plans to and there is plenty of cars they can buy today