I have a 04 WRB wrx. Next week I was gonna order a STI hood scoop to get more cool air onto the IC. Is there anything else I need to get. I thought I saw somewhere that there was some bigger air defelctor or something. Is that true? Thanks. I dont want to buy the scoop, just to find out I gotta spend even more money to buy a whole bunch of other parts to make it work.

 

No it fits perfectly. I just put an STi hood scoop on my 04 WRX last week.

You don't need the STi air splitter (which is the thing under the hood scoop if you open your hood) that deflects the air into your intercooler. That is unless you have the STi TMIC.