It will be a bit of a pfaff.
The new muffler has a smaller cat underneath where the big square one use to be. Is more like a bulge in the pipe now. The old cat was also a muffler, so if you keep it and add the new muffler it might be extremely quiet, if it even fits. So, if its legal for you, you'll need to get a new header that deletes the cat, otherwise get a 2016 header with the smaller cat.
Then, the GT muffler sits at a lower angle than the sport one because of the fat arse bodywork. So you might need to modify the connecting pipe, as the muffler is a different part between Sport and GT.
Be a lot easier to just get an Akra...
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