This unidentified autonomous Nissan Leaf was spotted in Mountain View on Castro Street / Villa Street on January 14th, 20120 at around 11:15am. The sensor rack on the roof was new, and resembles a bit the one from Lyft Level 5. Also Nuro.ai has been using initially Nissan Leafs as test vehicle, as well as JingChi/WeRide.
The car in front of the Nissan Leaf is an autonomous test vehicle from DiDi.
As always, any hints about what company is operating that vehicle are highly appreciated.
UPDATE: after I saw the two vehicles today at the same place again in the same order, everything seems to indicate that both are DiDi vehicles. Presumably, DiDi is testing two different hardware and/or software stacks in this way and comparing them by driving the same routes and scenarios.
This article was also published in German.