just to let you guys know i brought my car new in jan then it snowed the next day i did not drive it for 2 weeks. In the meantime i got a magnaflow cat back and airaid for the car it had 15 miles from the dealer to my house. I installed both and drove it till now. airaid off BIG BIG DIFFERNCE the car was better with it off!! went back to stock box after reading this forum and wow iam sooo happpy!!