Ive spent about a month calling everyone to figure out what to do to my 08 2.5i. The best thing i can tell you is to work on the suspension and the looks of your car. The OEM filter will work fine and you truly wont gain anything, wont even sound different. If you really want to you can make a hybrid intake and maybe get a lightweight pulley ^.^ thats what i did just to say i did it. lol best of luck fellow Subaru owner!