The auto parts don't stock them. Sold me the wrong one - 66548 - does NOT fit. So far I found one used on Ebay but I'm looking for some NEW ones. I have a 2012 Focus Electric.
I bought the same ones you did on Amazon for $90/set. My old ones were like yours, 66549.
2X D8S 25W OEM HID Xenon Replacement Headlight Bulb 4300K White P/N: 66548 New
Sold by: North State Auto Supply
However, a slight modification is needed. There is a notch that you have to cut into the new plastic ring. Just compare the old vs the new and you will see where it needs to be. I used a dremel tool to do it and it came out perfect.