Curious how all this worked out for you in the long term. I noticed the article is from 2015 (I just started with Medium). Are you still sharing your ride? For me, part of the worry would be this same scenario. But a much larger concern would be automated traffic enforcement such as red light cameras and toll cameras. In most cases, laws have been enacted that forego any burden of proof for the accuser and automatically ticket the registered owner. That could be a mess.