CoastaleTech has them listed including the 2013 Expedition. There was a firmware update in 2011 from what I can see on their website. I did a LOT of research before making the purchase. No difference in the 11-12 models I don't think. At any rate, I asked the seller on eBay if it was compatible with my 12 just to make sure and it is/was. Works perfect. I think I'm adding a front camera just for the coolness factor.
If you decide to do this, by all means get the plastic tools for taking the dash apart. It's well worth the 7-9 dollars you'll spend
Did you get the illuminated sill plates yet?