Over the summer I did a mid muffler delete on my 2016 Hellcat. Not that it wasn't loud enough for stock but just wanted a little bit more. A few months ago, I was watching you tube mods for Hellcats and stumbled upon MFER'S. I didn't realize that with active exhaust the drone is different in all the drive modes. Loudest when I'm in track mode. Any how, I made the purchase ($115) for two and installed myself. The install video was very helpful and install was super easy to do. Now when I start the Cat it sounds awesome!!!!!!!!!! Exhaust flaps stay open no matter what driving mode your in. Just thought I'd pass this on....