Aurora Innovation Inc. on Monday gave a glimpse of the vehicle with which it plans to test its self-driving taxi service. Produced by Toyota Motor Corp., with which Aurora signed an autonomous taxi partnership earlier this year, the vehicle is based on the Japanese automaker's Sienna minivan. Aurora plans to test a service built around the vehicles, which are dubbed S-AM and will feature Aurora's self-driving technology, in the Bay Area and several other U.S.