its not bad, its just expanded nitrous in the line and isnt as cold/dense as it was in the bottle. as for the 45° thing, i dunno, i never really had any noticeable difference in how it was setup, i just kept the knob side of the bottle up a little more then the bottom. i know a fast car around town who has his bottle sitting straight up last i looked but no, it doesnt matter if the bottl faces the front or the rear. and no nothing wrong with it behind the drivers seat...hell mine sat in the passenger seat strapped in with me in a cute little duffel bag