I hope he was talking about just the muffler section and not just one of those tips. Anyway, if you install a CAI and a high flow noise can muffler, you might get 1 to 2hp at the wheels. It's not worth it.
I'd also like to say this. If you people want power from this car, don't waste your money on these trivial parts. Save your money that you would likely spend on a new muffler, new rims, CAI, etc., and put it towards a turbo. You can get a turbo for this car for less than $3000. That really isn't that much money. Even if you are in highschool, just save up 80% to 90% of you summer job paycheck and you will easily be there by the end of the summer. That's just my opinion, take it or leave it.