you can totally tell that the fire spread from under the hood. It is very unlikely that someone tried to burn your car, starting it under the hood. Chances are, you crossed wires somewhere. If it were arson, even the most dim witted person would know to start the fire near the more flammable material (seats, carpet, gas tank)

Sorry for your loss homie, but the flames are ironic and really funny. Be glad that it wasn't in your shop or near a customers car or something!