FYI, I did this mod using legos, and it worked. But the 3-dimple piece on the bottom lego sort of straddles the two contacts on the control board. At least in my car, this made the rear fog button functional, but there was no feedback when you pressed it.
I read on another DIY that someone used a pen cap glued to a base of stacked credit card pieces. I decided to give this a try. HUGE difference! The flat bottom of the credit card pieces presses evenly on the top of the two contacts, as it should. So you get that punch-in-bounce-back feedback that all the other buttons in your car have.
Maybe someone could try gluing a piece of credit card to the bottom of the lego pieces to get the same effect.