Apparently a startup built or is working on building an after-market ADAS system for Hondas. In typical startup fashion they seem to have moved fast and broken things, failing to consider the regulatory environment in which they tried to introduce their product. The NHTSA would like some additional information on their product [1]. Instead Comma.ai decided this was too hard, gave up, and is taking their product to China.
Reading over the NHTSA's requests, I don't see anything unreasonable or that should be hard for them to answer. Maybe this is really just another Theranos fraud and they figured they better give up before they get found out.
[1] https://www.scribd.com/document/329218929/2016-10-27-Special...