Ive got the 6 disc Harman Kardon system as well, it’s a pretty well optioned SE with HID’s , blue tooth, cold weather package, 3rd row with rear AC, and parking sensors. The system sounds very good (to me) but something that adds apple car play and/or rear camera would be nice.
Here's the parts I went with to use the factory amp. It achieves the goals you outlined. Fairly happy with the setup, maybe sacrifice a teensy bit of audio quality ( and some more money) for quality of life. Hope this gives you a starting place.
1. 2 DIN dash kit from metra 95-9404B (~70)
- basically new housing and trim pieces.
2. Axxess DIS-LR92 w/ SWC retention (~400)
- this is the expensive part, but lets you use your factory amp off the fiber optics and retain steering wheel control of your radio. If you have the phone buttons on your wheel I can't speak to them. Caveat is that I'm pretty certain it knocks it down to a 2channel L/R stereo ( from probably 6-8 channels factory)
3. Metra 40-EU10 antenna to radio adapter (~10)
4. Radio of your choice. I went with a pioneer avh2550 nex since it had the right features. Came with a small mic I ran to sunvisor so now I have hands-free calling. A shallower radio would've given more room for all the harnesses and black box magic things behind it. This also meant I installed a little dongle from amazon to bypass the park brake software interlock on that radio so I can boot android auto on the go. (I also stuggled to get the park brake signal working) Finally- I routed wires all the way back for rear view camera (~30 amazon) and powered by same accessory power as the radio so I can use without having to actually be in reverse.
I think the alternative would be to pursue replacing the oem amp in order to avoid the fiber optics or maybe installing a dsp unit after the amp to split the channels back out. Would require some research.
