I had read a posting about easy performance upgrades a couple of months ago but can't find it now! Anyway, thanks to the guy that posted it. Ive got a 325 and got the Signature Motoring heat shield and the K&N filter for about $140 total (signaturemotoring.com) The power increase is fu%^king awesome and the sound is not any louder except and high RPMs where it howls! Very cool. I'm also getting 2.5 MORE MPG! Whole setup installed in about hour and a half (but I've got two left hands and take a cold beer after every half hour working). :D