Ronen, all I can tell you is, if you're bothered by buzzing/creaking noises now, don't even think about installing an aftermarket exhaust on your car. I have what is considered a quiet exhaust (Invidia Q300) on my sedan and I hear all sorts of buzzing rattling noises throughout the cabin at various rpm. Doesn't bother me a bit because I knew going in the WRX/STI wasn't supposed to be Lexus quiet. Look around you as you sit in the driver's seat. You're surrounded by cheap plastic. That plastic butts up against cold hard...metallic substances. It's going to rattle and buzz. Welcome to Subaru ownership.