well since its only used for the intercooler, then yes you can use CO2, but for now I'am using N2O, until I can find a place that can fill the bottle with CO2.
go to a sporting good store or somewhere that fills paintball tanks. unless thats not the same thing? i am thinking about getting one myself but i want 2 smaller bottles beside my subs. not really gona be there for anything besides looks and the purge. or did you find yourself using it once you got it?