Hello l have a longlife one on my IS 200,however I have a chambered back box instead of a straight through one as well as a middle box, as a result it is only just slightly louder than the OEM one on start up,and has a slightly deeper note similar to that of a BMW 325 for instance,which I like.I never wanted mine to sound like a boy racer as I think it spoils the car,so was very particular about what I wanted,so after only having the chambered back box fitted and finding it too loud took it back and had a middle box added,hope this helps.