Nice, thanks. I'm willing to do it (I've actually never used G+ or Twitter before...). I would think though if there is a LW user who Musk might have actually heard of, say through the Superintelligence book, then that would be more likely to get a response. In other words, I think if Eliezer Yudkowsky wrote to Elon, that could be a good thing.
Musk has joined the advisory board of FLI and CSER, which are younger sibling orgs of FHI and MIRI. He's aware of the AI xrisk community.
"I'm increasingly inclined to thing there should be some regulatory oversight, maybe at the national and international level just to make sure that we don't do something very foolish."
http://www.cnet.com/news/elon-musk-we-are-summoning-the-demon-with-artificial-intelligence/#ftag=CAD590a51e