well first i had gotten the cold air intake and i hardly noticed any power gain. then when i added the exhaust i noticed a huge difference. well not huge but very noticeable. i shopped around for exhausts and i got mine for a little over 500. now i dont know if its worth it. it does make the car go a little faster but its nothing like adding a turbo. its really up to you. i like to race a little on the freeway and that little extra power i got does help. so its up to you if you wanna spend that kinda money on something that will probably give you like 6-8 more horsepower even though most exhaust companies claim 10 HP. and if you dont know RS R is a very good manufacturer