I originally ordered the 18s but bought the 12s off another member just to see what the difference was. It seemed pretty minimal to be honest, it gives the idle a little more growl but i think the main difference is with the AC on. The 12s can get pretty loud. People are really aggressive when i have the AC on because it seems like im reving it out but im not
Guess that goes for any loud exhaust hah!
I really enjoy the 12s though, it brung up the volume enough for me to where its not completely ridiculous. I can still drive it keeping the volume down but whenever i want to make some noise it isn't hard
I can try to get a video in cabin with windows down and up maybe.