Hi there...I'm not sure if this has been brought up before...
I'd like to see EMS/Rescue units start out as Basic Life Support (BLS), and staff having to get trained to Advanced Life Support (ALS-Paramedics). This could open up different levels of calls, paramedic rover vehicles, etc.
Another EMS thought would be to have Tactical EMS...these employees would also need to be trained, like SWAT, and they would respond to calls with SWAT.
Great job on the game...keep it up!