Bunch in the car, ads?

Hello, yesterday someone drove into the car. A fist thickness bump in the back. Where exactly this happened I don’t know, but definitely the culprit is gone !!! Has apparently seen no one either. Was most likely when shopping, on the shopping center parking lot. What should I do now, should I still make a report? The chances are rather bad to find those. The color of the other car can be easily recognized !!! Thank you…