I posted here about speaker replacement to improve sound, but I'm considering replacing the radio in my 2015 Fit EXL now. My concerns in doing this include:
Loss of factory BT
Loss of USB ports in center console and center stack
Loss of steering wheel buttons (although there may be a way to retain those with an adaptor)
Loss of any programming features contained within the radio. Things like MPG history and lock programming?

I'm not that much of a DIYer so I'd be going to Crutchfield for plug and play solutions.
Feedback appreciated here

 

Yes and also loss of lanewatch, backup camera and HDMI ports.

Depending on your choice of headunit, if it supports a backup camera, then you can retain that and lanewatch.

You can retain most of your steering wheel functions (volume, next/prev track, source). You will (probably) lose the two buttons to the right of the volume disc (one is menu, can't remember the other one).

Right now I am trying to get Bluetooth to work, but honestly I never liked the Fit's controls anyways.

There are 2 modules/adapters on the market (that I can find) for the GK5. One is made by Axxess so you'll need ASWC-1 for the steering wheel controls, and HDCC-02 for the lanewatch/backup camera retention as well as providing power to the new headunit. The ASWC-1 needs to be hardwired into your system. You cannot plug it into the HDCC-02 and expect it to work (it doesn't even though it says that it can). If you simply wanted to plug and play, then the ASWC will disappoint you.

I initially had a problem with getting any camera image. A call to Axxess and I cut and swapped the input for the HDCC-02 and it worked. My problem is that sometimes lanewatch gets a fuzzy/distorted picture, so Crutchfield sent me another module. I have yet to give this a try.

The other adapter is made by PAC (PAC RP4-HD11 Radio Interface). Their instructions are much better compared to Axxess. If the Axxess lanewatch still gives me problems, then I'm returning it all and going for the PAC.

As for USB retention, I tried some adapters to fit the OEM USB ports to my Kenwood headunit, and it fried my flashcard. I will just tape the Kenwood USB inputs to the OEM port opening. I am trying to buy an official Kenwood USB extension for the center console.

For HDMI, I am working on a quasi workaround.

For the Bluetooth unit built into the headunit, I routed the mic to fit between the sunroof controls. In the owners' manual, it says the OEM mic is here. It is not. It's a grated opening covered in the back by black plastic housing (which also holds the sunroof controls and lights). I dremelled off some of the black plastic to hide the mic behind the holes. People can hear me perfectly.

You will also have to purchase a Metra dash kit. They come with some pretty pathetic plastic headunit braces. I was able to use the OEM metal ones. I also bought some M4 screws and washers to hold everything together.

You'll need to take apart the instrument cluster bezel, the part of the dash that is over the center vents, and for good measure the passenger side dash that is just over the glove box.

 

Forgot to add you'll also need to take apart the cigarette lighter assembly.

If you're not adding any amps, then the HDCC-2 will come with speaker wire connectors.