How about a thread with pics of extinguishers mounted?
Like this one?
http://naxja.org/forum/forumdisplay.php?f=43
Excuse me for disagreeing with NOTINSUV.
Ignition is not one of the components of fire, it is a result of all 3 being present in the correct proportion. Race cars have a kill switch in the back to prevent electrical ignition before the fire. Once the car is on fire, it's too late to prevent ignition, so you have to worry about the people, then the property..
Fire is simple guys, remove one of the 3 components (Fuel, Heat, Oxygen) and you don't have fire.
Your average ABC Extinguisher does this nicely. It will work on wood, liquids, and fires caused by electronic ignition and it does so by removing one (or more) of the 3 components of the fire. It will not work on fires that are self contained, like a flammable metal fire, but we don't see very many of those in an XJ.
* Should you carry one? Yes.
* Should you get training on how to use it properly? Yes. Read up on P.A.S.S. and preferably get the opportunity to use one in a controlled practice setting.
* Should the extinguisher be within reach of the driver? Yes.
Why? Because even if you have to step out of the vehicle to get it, the extinguisher is able to be deployed more rapidly than if it was in the back under the groceries. Remember, it may not be your arse you are saving, but someone else's. As with any 1st response, time saved is the answer.
My thoughts on this entire subject can be summed up nicely. If you can prevent a fire (though better engineering, careful planning, fore thought, maintenance, or whatever) that is worth a whole store of fire extinguishers.
-Ron