Even in a future of robot taxis, someone still has to return the things passengers leave behind.

Aurora, May Mobility, Motional, Nuro, Tesla, Waymo, and Zoox all refused to cough up a number during Senator Ed Markey's recent investigation.

The launch comes just two years after a major reboot at Hyundai-owned Motional. The service will start with a safety monitor, which Motional hopes to remove by year's end.