@timbo - The keypad is great. I use it all the time because I surf and windsurf in the ocean and don't want to stash my fob or carry it in a waterproof pouch.
If I lose my fob for some reason, I always have a way to get inside the van where I have a spare key stashed.
As you can see from the pic below, I mounted mine on the rear door because that's what I mostly use for getting gear in/out and the location is most accessible.
You first program the keypad like a normal keyfob and then mount it anywhere with adhesive. Don't think it will come off on it's own. Battery is supposed to last 5+ years, I think.
There is another thread about setting up the keypad (see link below). Very easy process.
http://fordtransitconnectforum.com/topic/2991-keyless-entry-keypad/?tab=comments#comment-8793