Got my onboard air system installed.
Drilled 4 holes into the top of my cargo box and mounted the Powertank bracket, and it is rock solid.
http://www.pnw4runners.com/fj/powertank_bracket.jpg
Powertank installed
http://www.pnw4runners.com/fj/powertank.jpg
I bought this tank a few months back to replace my black one I use to have in the 4Runner.
I had to let that tank go a few years back when I was on my layoff from Boeing.
I like C02 as it is very fast, faster than an air compressor.
One 10 lb tank will refill about 30 tires from 15 psi back to street pressure after 4wheeling.
You can run air tools with it too.
Here is a very old video of my taking off my lug nuts on the 4Runner to put my winter tires on.
http://pnw4runners.com/tando/impact.mpg