Has anyone replaced their rear view mirror with one of the mirrors that have the built in garage door opener?

I have a Homelink mirror in my other car and like not having the garage door remote hanging off of a sun visor.

The mirrors with the feature built in require wiring, and are relatively expensive - considering a new shiny remote is about $20, and my old one is free.

I was hoping to find a battery operated model that would allow me to just slip off the old mirror and on with the new.

I'm guessing Homelink has some sort of patent on this technology, keeping others from incorporating it into replacement mirrors.

Any creative solutions for eliminating the sun visor mounted garage door remote?