if you know who hit you and could provide the evidence, you wouldn't need the comprehansive coverage. Otherwise, this is treated just as some stone fall from the sky and hit your car and you will need comprehansive coverage for the insurance to cover you. If you only had liability, you would not be covered. Under such circumstance, if the damage does not cost you too much, even if you have the comprehansive coverage, I guess one not to claim the insurance since the premium will increase the following year. The insurance company now believes that you often go to places dangous and the chance of your car being damaged is high (this is the same as different locations have different rates).