The panel containing the buttons contains blank button faces. It's modular so if you had the kit, you simply pull off the seat heater faces and put on the corresponding blanks in their place.
https://www.ecstuning.com/BMW-E92-M3..._All/ES168433/
I have the kit but I'm planning on using it for another project to stealth up some of my add-ons
But, the piece you're wanting, I actually ordered a few months ago as mine was peeling. I'll get you the part number when I get home.
Edit: here you go, part number 51459118703.
https://www.ecstuning.com/Search/Sit...8703/ES119249/
