I would fight it and easily win . Police officer got no proof who was driving the vehicle. Register owner is not responsible for the action of the driver. So unless they could id the driver, it wasn't me driving will get ticket dismissed.
All ambulance crew needs to understand that unless cop is around a siren on ambulance is there request permission to pass being that you can't issue a driver a ticket for refusing to get out of your way. As such it's the driver if he/she decides to let you through or not. Blasting your siren or using your pa is not going to get you around me as only thing it will do is get a middle finger from me. Writing my plate will not help you as an officer needs to witness the violation before he/she can issue a ticket being that an officer would need to pull me over to issue that ticket.