Let me know what u think

https://youtu.be/S9-vn-SEOAU

I really need to add USB! Looks like a lot of work lol

That's a lot of work for something very simple to accomplish. A wireless charger can be powered and connected all inside the arm rest then fastened to the fold-down organizer lid. Then simply place your phone on top of that for wireless charging.

Take it a step further get an arm rest organizer and cut it down to create a compartment to the exact dimensions needed for the charger and a phone. This way you 're not tied down to the lid like I mentioned earlier. It doesn't require taking your dash apart to add modern features to a car, just ingenuity.

That video was about adding the GROM bluetooth system. The video that details in-car charging is here:

That said, I think it is brilliant, and probably the best way to add in-car charging. It will only work on the older M's that have that little pocket next to the seat temp knobs.
I am currently pondering and planning an equally brilliant way to accomplish this in the semi-newer M's like my 2009 that do not have that little pocket bin. Ideally, it will use the surface charger accessory that comes with, or can be added to your exact make and model cellular phone. I will post a DIY when I have worked out the best location, the best wiring design, and have tested it on a daily basis.