I carry two. The one that is mounted between the seats, on the tunnel, and that doubles as a perfect arm rest, is a Halotron unit. It is a "clean" unit, and leaves no residue. The second unit is mounted in the trunk to the roll bar brace. It is an old fashioned ABC powder type extinguisher. If my car catches on fire, I will use the Halotron unit on it. If your car is on fire, I will use the old fashioned unit and then you'll have to use Q-Tips to clean up all the white residue, but at least the fire damage will have been lessened.
