Da Groj

Fire extinguishers are a stop- gap method until the fire department arrives, if there is a fire under the hood, the preferred method is to aim the extinguisher nozzle under the wheel opening, into the engine compartment (or from that area), until the fire is out instead of opening the hood. There are a multitude of hazards in car fires, from plastic fuel tanks to the little hydraulic struts that can become missiles. In short, if the fire is small, go for it, if it has involved the engine compartment, call it a day and walk away from it. BTW, try to make sure the car is left in neutral (or chock the wheels)so the starter doesn't short and cause the car to move on it's own
There, you've heard it from a state certified fire instructor.

Not to argue, but how many of us drive cars without fender liners that are specifically designed to keep rain out of our engine compartment? How effective is aiming a fire extenguisher into a wheel well going to be against an under hood fire?

The relevant part of what you said is "if the fire is small, go for it". We don't need to try to be heroes out there. If the fire is obviously beyond putting out with our garden-variety extinguishers, we just need to stay out of its way.

What I put in the driver's meeting notes was essentially what I Googled: "pull, aim, squeeze, sweep". I think that's about as much detail as we need to get into at a driver's meeting.

Please note "or from that area", in other words, not from the front of the vehicle.