I have a 2009 WRX. I was talking to my buddy who knows a lot about cars but not so much about Subaru. I asked him if getting a short ram intake was good because I've been told in multiple places that CAIs are not very effective on the WRX. He told me that getting just a normal K&N cone air filter instead of a SRI would be cheaper and less restrictive than the normal intake and the intercooler would cool the incoming air anyway (duh), eliminating the need for CAIs and SRIs. My question is: Is he right? Would the SRI or the K&N be a better option on the stock engine? What do you guys have?