I have been monitoring this as I wanted the HomeLink on my 2014 Fusion. I had several problems as I wanted to use it to control a garage door and a gate opener and the two were not compatible.
The Ford Fusion part of my solution was to purchase a HomeLink installed in my sun visor by a guy down in Houston. I located and dealt with him via. eBay. The price was $125 plus $15 shipping. You ship your visor to him and he returns it with the HomeLink installed. It is cheaper if you install yourself as some above have.
search on eBay with: HomeLink installed in your lighted sun visor
removal of the visor can be tricky. I have a document with instructions but I am not sure how to post it here.