Sadly i'm talking from experience when i say that you'd be about as well beating the fire out with one of those. They'll buy you seconds, nothing more, against a fluid fire.

I personally have a Lifeline Zero 360 plumbed in system in my track car as well as a 1.5 Litre Zero 360 handheld.

They're about the only thing that i've seen have any knockback ability on a vehicle fire!