Biggest challenges were replacing the factory USB/AUX port under the AC controls and finding the right antenna adapter.
The replacement USB/AUX is not a perfect snap-in replacement for the factory one, but I did not have to cut and splice wires.
I did have to modify the case and am using silicon to hold in place.
It's a little late but all you needed to retain your OEM USB is this Maestro adapter.
It what I used in my 2014 SR5.
For some reason the cheapest place to get it is BestBuy online.
One cannot use the AUX plug with this adapter, but most people don't use it anyway with USB and Bluetooth connections available.
I also ended up installing an HDMI to mirror to iPhone with an additional USB plug in my driver's 12v socket hole.
This USB is the #1
USB to the head unit and the #2
of the HU is the OEM plug.
I don't use the HDMI like I thought I would and I wanted to use the additional USB to charge the wife's phone when needed.
BUT, when I plugged her phone in to the #2
USB of the HU, it would put and 'incompatible device' error on the screen I had to cancel out.
Since I wanted a more precise amp meter, I replaced the passenger 12V plug with a meter with 2 powered USB port to charge her phone and all my other USB stuff.
I really don't need a 12v socket and if I had to have one I'd use the one in the console.
Just food for thought to whomever may be reading your thread.