Question:
What's the best way to secure a fire extinguisher to a padded roll bar. I don't like the way big hose clamps look and I think drilling holes and using self tapping holes will be unstable (remember it takes three nonlinear holes to define a plane, I just scared myself) and I believe the vibration would enlarge the hole with time.

Answer: -Not on a rollbar but what I did was fabricate a piece of mild steel and hammer-form it to the contour. (seat bolts) Then mount the fire extinguishers stock bracket to the steel with bolts, cut off the part that stuck through and swaged it in place with a metal punch. No problems to date.

-My 5# extinguisher's spring-steel holder is bolted to the bottom of the seat frame in front. While that would seem to be in the way, it's not but it's right there when I need it. Grab it and it'll pull out of the holder without unfastening anything. The holder holds it *very* securely so it takes a strong direct pull to dislodge it.