I have a multi piece intake that is in fender at full length and I believe is short ram if you leave off the last piece.
Pictures and details are in this thread.
http://www.seccs.org/forums/showthread.php?t=5863
That said, do you have other mods and tuning to support the CAI? Typically, a CAI is very low on the list for a WRX as the stock box can handle about anything you can throw at it except a huge laggy turbo and FMIC.
Otherwise, a CAi might well be a big negative, not an improvement.