def dealer added.. I've seen a couple people get it from the dealer with it already installed before purchase. You can also add it yourself easily.
FWIW I went the double apex route and the quality of the switch and components are top notch. It has the added benefit of filling in one (or both) of the blanks around the shifter.
Mine didn't have homelink, just auto dimming.
The dealer looked up my VIN and said the OE homelink mirror wasn't compatible. I ordered it from DAP anyway, and it wouldn't fit. The base that snaps over the bottom was physically too small. I went old school and did went with a garage door opener on the visor.
Did you install the double apex yourself? If the dealer did it, what did they charge for labor?