It is true probably at WOT but not the correct WHP due to drivetrain loss which amounts to about 15-25%. I do have the Injen installed, and you feel it above 3K in RPMS... but you lose some low end power. Lots of threads about CAI and SRI all over the place if you want to do some research.
An intake could give you 12 HP. You would need some kind of tuning aide. Like an Apexi SARC II. You would need to also do it at a dyno and you might be able to get about 8-12 hp if you correctly tune it. Bolt ons don't really give you any power, to see the true power you need to tune the car correctly. So, it is possible to get more then 2 hp out of it, and you might even get 12hp, I would prove it but I don't have an intake, but on the other hand I do have the Apexi SAFC II.