So, I've been looking at this HKS Hi Power Silent axle back for the GK5:

silent Hi-Power?FIT

The thing is, according to the second link: "Not fits to "4WD" and "CVT". I emailed an American HKS distributor and they told me the same thing (although they may have just been quoting the website without having any real knowledge of the differences).

It seems kind of weird to me that the exhaust would be different between a manual and a CVT on a front wheel drive car. It doesn't make any logical sense for them to be different, since the differences between the CVT and MT are all going to be toward the front of the car, definitely not axle-back. So, I took a ride to my local Honda dealership and checked out a MT Fit they had on the lot.

I can't really see a difference in the exhaust from the axle back between the CVT and MT. Visually there doesn't seem to a be difference.

2015 MT:

http://imgur.com/pyCvPR2,c9Jzn1A#1

2015 CVT:

http://imgur.com/pyCvPR2,c9Jzn1A

I guess I post this in hopes someone with a MT sees it, and maybe make some measurements and snaps a few better pictures (I was on the car lot, didn't want to look too weird).

 

I'm looking at the Honda parts catalog and its showing me that the OEM/Factory muffler is the same on both the MT and CVT GK5s here in the US on all 3 trim levels. So with this said it seems like the HKS should fit; however, do keep in mind that the HKS is installed on a short nose (shorter front end and rear bumper) Fit so it may or may not clear the rear bumper if installed on your's. In a similar fashion like the Spoon N1 would end flush under GD3 with a JDM/EDM spec rear bumper and be tucked under a USDM/CDM spec rear bumper.

 

I also have been eyeing this axle back system. Are they avaialable for sale already? That was the thing i was looking at too on their site (that whole not for CVT note)

 

So now that you know that there are no differences between the US spec CVT and manual trannied Fit stock muffler and that it doesn't make sense that the automatic and manual Japanese Fit would be different from each other, are you going to purchase the HKS muffler now?