All,
I would suggest a more secure method of mounting an extinguisher than velcro. If, and I hope it doesn't happen, you have a crash the forces involved will probably mean that a 2Kg extinguisher turns into a missile with the same force as a 2000kg extinguisher, not good when it comes into contact with a person.
this applies to lots of "stuff" people leave loose in their cars including umbrellas, boxes of tissues, pens, books, maps, mobile phones etc etc.
Having been in a couple of crashes in the rally car I know that even to hold onto a clipboard and pace notes is pretty difficult and the amount of stuff that flies around is pretty scary. Thank goodness for crash helmets.
Malc