ScottG wrote:
Unless yor son is added to your policy, it seems like the coverage is rather muddied.
An ins. co. will use any loophole or excuse to get out of covering a large claim.
Insurance is a highly regulated industry.
Insurance typically follows the vehicle. As your son is a listed driver on your policy, a permissive driver, as another poster just mentiined, the liability coverage on your truck typically cover the trailer as well while it's connected to your truck. But as the trailer is non-owned, I'd double check with your insurance agent and have them send you an email so its documented in writing.
As you said, your son would need to buy his own PD coverage for the trailer. Good luck.