The DoD and the police also have software which pin registers a specific object in a series of video frames and then stacks them and uses median filtering to achieve a significant blur reduction. Unfortunately, I don't have access to this SW any more, but as suggested earlier, if you can convince the police that this crime is sufficiently significant to warrant the expenditure of forensic resources, than you might be able to pick out the characters. For a collision with only property damage, I doubt you will be able to rouse their interest in doing this.
This can also be done manually, but it is **EXTREMELY** tedious. Typically a hundred frames or so must be used to see appreciable improvement.
HTH,
Tom M