Tips to evaluate Autonomous Vehicle startups?

I am an engineering & product manager, evaluating autonomous vehicle companies/startups to join. While I know how to evaluate consumer hardware, software, and products, autonomous is a little bit of a dark art for me right now with every company saying that they have a great approach.

I met a few of the startups, and they want me to come for a full round of interview. Before I do that, I want to form an opinion on what to look for to evaluate whether the company will succeed or not.

I am wondering if the community has any tips, questions or research to make a decision.