I asked the same question about a year ago and was told Quicksilver also. Pretty pricey though. In the interim I went to an exhaust dealer I’ve used before to get a different muffler just to give my epace a subtle ‘note’. $800 compared to several thousand. I was also very conscious of not affecting the warranty. Depending how long I keep the car I may treat myself to a Quicksilver system down the track.