On that picture you can see a speed camera locator :
I bought it because its head up display function.
Here it's only displaying ---- as the speed is under 10km/h.
I haven't put the transparent film under the wind shield, but the visibility is OK.
I wanted a speed head up display but on after market they are all expensive and complicated to install : they need to be connected to the speed sensor signal...
This speed camera locator is much less expensive and as it's based upon a GPS receiver it doesn't need to be plugged anywhere excepted to the 12V plug. This permitted us to install it in less than 1 minute in my wife's car during holidays...
For people wondering what is the new switch aside the kill switch,
read here 
Have fun,
Denis.