Art - maybe this link will help. I did not know this about car insurance.

Your car insurance is primary if you are the owner of the car, even if someone not named on your policy drives it and gets in an accident. I.e., your insurance pays if it's the car they insure.

I would still want your son named on the policy - not just for peace of mind, but also when he applies for car insurance of his own, it will help him get it if he has been covered previously and can prove that. And there are benefits to sticking with one insurance company for a certain period of time, like accident forgiveness - does your current insurance have such a policy?

Maybe your husband and you need to talk this through a bit more.