State law prevails.

In NJ, I couldn't get my girls covered on my policy as teenagers, because they did not live in my home. They were covered under my policy to drive my car(s) as occasional permitted use drivers. They banged around a couple of cars pretty well.
My insurance company, not the ex-wife's, paid for all accident claims which happened when they were in my cars, both personal injury and physical (property) damage.

Boy, I'm glad those days are over. Nothin worse than the anxiety of a 2:00 am phone call.

Good luck Danny.