I dunno much about burning cars. Is this effective? Seems like dumping it underneath might result in a better fire, but not as showy for the camera. The windshield doesn’t strike me as a particularly flame affected area, but it looks like a bunch drained down into the engine bay.
I'm guessing it flows down anyway, if it gets to the plastic in the interior of the car, I'm pretty sure it will burn out completely. Maybe gasses will enter through the air intake when you pour it on the windshield, or maybe the glue holding the windshield, will lead the fire inside? Which will probably cause total burnout. Also if the glass cracks that will do it too.