Here is a list of everything I used below. I was able to retain all the factory features and use the factory camera. I haven't really found any use for the HDMI but might put a Chromecast or something in there one day (I wired in a parking brake bypass to allow video in motion).
*PAC RP4-MZ11 - Allows you to retain steering wheel controls and change the clock and MPG info on the display.
*Rerii USB panels - Installed these in the center console (one in the place of the factory cigarette outlet). I mainly only use one for now with Android Auto. The other one is for Apple Carplay or AUX.
*12 Volt step down - Used to convert 12 volt from head unit to 6 volt to factory camera.
*4 Pin female camera connector to oem harness - I originally made my own adapter with some PC headers but didn't like the distortion I got on the display. I found someone on the forum that made a plug and play connector.
*Parking brake bypass with triple pulse - I read some people had issues with the double pulse after Pioneer updates so ordered a triple to see if it makes a difference.