Petrol in spray form is not flammable, its explosive. Forget the cars battery, there can be a ton of sources that can ignite that mist
E.g. the motor windings of the aircompressor they are using.
I have witnessed petrol vapour explosions, your vehicle would be completely scrap metal when that happens. And if i saw that in my presence, i would beat the operator with a stick to within an inch of their life.
