This is what I ended up doing for my XAV-AX100 as I didn't want USB cord laying around inside of my car.
To retain steering wheel control, you need something like this
https://www.crutchfield.com/p_541RP4VW11/PAC-RP4-VW11-Wiring-Interface.html?tp=3486
I am able to use following functions: skip, previous and volume control.
After switching the coding In VAGCOM, I can use voice control button as mute(significantly drops the volume).
Sent from my SM-N950U using Tapatalk
I did something similar when I installed my XAV-AX200 which I use Android Auto on. I used the Double Apex USB pass-through port, but put it in the center console where the stock AUX plug is, since that plug is useless to me. Then I have a 1ft USB cable going from there to my phone, which I keep under the ebrake. It is the perfect length to fit nicely and not have a bunch of cable all over, and keep my phone secure. I had to trim some of the backside of the USB port, and put it sideways for the best fit without modifying the console itself. I also used some paint thinner to remove the "USB" label from the cover so it doesn't look odd. Came out pretty awesome I think.
I used the same item linked above to retain steering wheel control.
A quick charge USB port is going in the far right switch location in front of the shifter for passengers or if I need some juice quick...
Also, for the stereo's microphone, I modified the ashtray I bought to replace the useless storage compartment, and put the microphone in there, coming up through it. It stays out of sight, and works nicely...