You made the report to the CHP. Once they identify the suspect or suspects, they will likely forward it to the DA who will then make the decision. It is the DA that has that ultimate decision. About all you can do is keep in touch with the CHP officer that made the report - or his supervisor - and ask about the status of the case. If they do identify a suspect and forward it to the DA, you can then talk to the DA's office and see what they intend to do. But, you cannot force them to go to trial if they do not feel it is worth their time. And, quite frankly, unless the suspects are local or have a past history, I doubt that the DA is going to be too excited about pursuing the matter for a mess to your windshield.
Okay, so 23110 is not an option. That leaves only 240 as you were not actually battered and there is no real chance of being harmed by a cup and liquid on the windshield ... hence the assault charge as previously mentioned. Though I am surprised that the CHP took the case and not the local police or sheriff's office. You might find that if you cal the CHP that the matter was turned over to a local agency for investigation.To elaborate on the position of my car..
We in the drive-thru with no way of backing out, turning out or moving forward. He was walking towards us and we literally would've had no way of defending ourselves had he actually approached the vehicle. We were stationary (car was on, had my foot on the brake or in park.. at the moment I can't quite recall)
While you might not want to hear it, this is not going to get the police or the prosecutor excited. Unless you and the suspects all live locally, it is unlikely the police are going to work too hard to pursue the matter. They are not going to send an investigator to some other part of the state for a low level misdemeanor. If the suspects live out of the area, I doubt the matter will be pursued at all unless the owner of the vehicle is otherwise wanted for something.
But, you can certainly all the CHP office that took the report and see what the status is and then keep making contacts every few days to see what is being done. Maybe, if someone knows you are interested in pursuing it, they will follow up and address the issue if the suspects are not too far away.

