told ya its expensive 
and yes, it's a type force induction.. NOS provide more oxygen to d engine.. same like turbo & sc.. but different method..
Turbo : Mechanically compress air using exhaust gas
Supercharge : Mechanically compress air using belt
Nitrous oxide system : Chemically compress air using its chemical properties
and u need forged internals to use any of d above.. no excuses.. or else..
Gudluck 
---------- Post added at 10:47 AM ---------- 6 hour anti-bump limit - Previous post was at 10:40 AM ----------
oh.. about d legal matter..
ANY MODIFICATION OF ANY KIND TO A STOCK CAR IS ILLEGAL.. (that's include a open pod air filter)
unless u can sweet talk ur way out with d JPJ officers
Gudluck 