@maple This is the most I can find: http://www.greenbulb.com/ssmirror

There was also a lifehacker article from 2010 which basically goes "just buy a mirror and glue it on." It specifically mention hardware store inspection mirrors. It's not the best looking thing and probably not what you're looking for, but it's an option, I guess. Here's the referenced Instructables article, if you're curious: https://www.instructables.com/id/Self-Portrait-Camera-Mirror/