If you carry a fire extinguisher in your car, the first thing to do after ensuring that it is for auto's is to be sure that it is strapped down properly!

Having a high pressure tube flying around the car in the case of an accident or a sharp turn, is not a good thing.

I remember seeing a Tractor pull where one of the safety officials had one of the new Halon Fire Extinguisher's. That night the tractor that leveled and smoothed the track caught on fire no less then 4 times. That Halon extinguisher put it out FAST every time, and that was just a little Extinguisher that he had on his hip.

If you can afford Halon, I would go that direction. If you can't, the dry chemicals are great,, till the fire department shows up and soaks the car and now you have caked and hardened dry chemicals.

Personally, my reason for saving my car is not saving the car, but rather saving the gear in the car. In the case of an emergency if you load up your car with all your necessary gear and then are stuck in traffic and your car catches on fire due to the long idle time, and some dripping oil or some flammable fluid, then you want to save the gear in the car and less the car itself. My thoughts on putting out an auto fire is less the car, and more the gear and hopefully tending to the car to get to safety.