I'm surprised at that, when I did rescue we were told if the crew were out to leave the car to burn/call local fire brigade to deal with it, the reason being that once we had used our fire extinguishers we could not cover a stage re-start or another stage, and without a rescue ambulance a stage could not be run.
On all the larger events over here we always have a spare rescue, ambulance & doctor/paramedic in case any one of them has to deal with an incident & take a casualty to hospital. But at this incident some of the following competitors used their hand held extinguishers to try and extinguish the fire. Unfortunately that meant that their rally was over too as they can't compete without working extinguishers! There was a bit of a row when they were asked for their time cards!
Most of our events take place of closed public roads & any residents who live on the stage are advised that if they take ill they ring rally office & not 999 as the emergency services cannot reach them until the stage is stopped. This has saved lives in the past as the rally medical crew was able to get to the victim of a heart attack a lot quicker than the 999 crew would have and saved his life!