More advanced fire behavior

Well, don't people know about fire, and the way it behaves? Fire needs three things:

• Oxygen
• Fuel
• Source

In the game, the fire keeps burning, and never lightens up, nor gets worse, and there's no damage inflicted on the vehicle. When a car hits a pole, and the fire begins near the front end of the vehicle, or wherever the engine is, right? So if that's the case, why doesn't the fire spread around? If there's another car right next to it, like if there's a car crash...

More advanced fire behavior