I would contact your insurance company, let them know whats happening. Very likely a few calls will be made and the problem solved. You likely have an adjuster or another desk jockey that view the car as a used car.
It could be a simple conversation could clear the matter up.
The nuclear option is to sue the guy who hit you.
I know it's not what you want to do, but the reality of it is, he hit you, you have a loss and you should be made right if his insurance isn't willing to. If his insurance isn't willing to resolve the issue, that doesn't take him off the hook for his actions.
If you have to go this route, be ready to fix the car on your own dime. Keep every receipt and log every second you spent on the repair.
Likely what will likely happen is, he will call his insurance company and it'll get settled before you get to court.
On a side note, you say this happened a couple of months ago? I wouldn't be above asking for a third party loss of enjoyment of property claim. You lost out on the last of the cruise season.
