I remember reading something about this in AutoSalon or Street Machine...
It was something along the lines of it is fine to have it installed... ...and a full bottle in the car... ...As long as it takes a good bit of work to get the bottle hooked up... ...and just as long as you're not driving on the road with it hooked up you'll be fine...
I also asked my local police contact and he said you'd be, and I quote, "A f$%&ing try hard wanna be that would get a defect from the first rookie ass kisser trying to get in with their SS(Senior Sergeant)"...
I'd say put it in a trailer queen or a track car... ...and just keep it off the street...