I am with GA Farm Bureau insurance, and after I had my hit and run, my agent told me that he would not be able to find out the insurance company or any other information based on the tag number. Who knows though, maybe he was just limiting his involvement. But one thing I think we can all agree on is that going through the other guy's insurance agency WILL require a police investigation. They have to confirm the damages to both vehicles before any repairs will be authorized by the opposing insurance firm. Again- the damage to my car was not that severe, but perhaps you might be better of just taking care of it with your own insurance company.