Something that I thought of while planning future rural fire stations is that some of them have a medical first response model that isn't currently featured in the game. It could be implemented as an extension, but it would have to be available to small fire stations as well. Basically, you would have the option to buy a utility unit or a mini pumper (type 2 Engine) that was designated medical first response, that would treat the patient to the same extent as a fly car would, but not transport. You could then also use it for your fire calls as a normal fire unit. You would also need it to show up in your ambulance drop down when dispatching.
You could also create a new fire course to go along with this to train staff in medical first response, or, as has been suggested in a few different threads, make it an EMS course so you can implement EMS training facilities (although you would then need it to accept fire staff, but I don't see that being much of an issue).
I can see this making the most difference for North America, where our rural EMS stations are far apart and the MFR Fire Departments fill a gap in service.