There was another thread in the Focus section not long ago, but now buried abut 12 pages down in the forum - http://www.fordowner...k2-focus/page-7
This is my set up, just behind the driver's side of the rear view mirror using a custom made mount. I can just see a corner of the rain sensor cover but it doesn't bother me. The most important is that it is put of sight from inside and out and sees whats ahead of the car. Works a treat.
Here is a picture taken from the driver's door.
Here is a picture from the outside facing directly into the wind screen