Rural Ambulance Crews Have Run Out of Money and Volunteers (nytimes.com)

In Italy ambulances are almost always run by volunteers. The rationale behind this is that most of the time when they are called, it is not something very serious, but when it is (like cardiac arrest) they are trained citizen who need to pass a rigorous exam and every hospital also as a emergency car with a medic (usually a rianimator) that can be sent along the ambulance if needed. I do not know if this model is used in the rest of europe