The new 9th gen Si axleback will not fit the new non-si they way it did for the 06-11 cars. You need to find a used 8th gen si or an axleback made for your car unfortunately. I found out the hard way. Hahahah..... you would have to take both to a muffler shop and have the flange cut off and welded on from the r18 to the Si muffler.