I'm just saying I've programmed two other cars' Homelink (Merc and Lexus) without a handheld remote so it can be done. I understand why Tesla would want to set things up to read the signal from an existing transmitter, but other car manufacturers have other solutions.
Pulling the wall mounted remote off of the wall, and holding it in front of the bumper did work. Odd that on a wall 4' high, 4' away from the bumper failed, but in my hand, 2' high, 2' away from the bumper worked. Is the search really that sensitive to signal strength?
Anyway, the car can open one door now, but not the other, as the wall mounted remote doesn't work with the other door, either. maybe it's the wrong frequency?