I had an exhaust added about two weeks ago and have a valve on a remote to bypass the silencers. This makes it louder and deeper around town but gets rid of the drone at 70mph. I normally drive in the louder mode but it is nice to have a more muted sound for early mornings/ late nights. The note from the car is much improved , up to 4000rpm in particular, with a great burble under load. It is not quite as good a note as I had with teh Larini exhaust on my last car but it certainly makes me want to keep the Lexus for that little bit longer.