I haven't contacted my insurance company about it yet. I guess I'll get it all squared away after I get my Model 3, as I'll have to shop around anyway. $60 a year is quite a deal, though. I was expecting quite a lot more.
I'm adding solar panels (no Powerwall though) and it added $38/yr to my insurance. They said coverage is similar to my roof regarding storms, etc. I don't have the panels installed yet so I haven't seen the details on the policy.