Oops, sorry, I mis-read the last line of the post - I don't know if you can do it then, because it would probably involve taking out a whole new insurance policy and then having your husband added to it - which is the owner's responsibility since the car shouldn't be on the road without insurance anyway.
Another thought is that if your husband has insurance on a different car (i.e. your own), maybe he could add this other car to it for a couple of days. I don't know if this is possible though.