Friendly word of advice: if your friend isn't extremely knowledgeable about turbo-charged cars, and subarus in general, I'd advise sticking to a pro-tune or the canned tunes that the AP comes with. It is relatively easy to mess these cars up with a bad tune (not to say that it'll blow up or anything that drastic, but that you can screw up a good thing - but the good thins is then you can always revert back with the AP).

There are tons of guys on here that are very knowledgeable who can help you out if you need it.