Just came to my mind that it'd be great to place a RD to the back window of the car, very high, just below the brake light. It'd be facing forward and "see" through the front window very well. It'd also get the rear signal without a problem and would not be visible from the outside.
For sure that kind of install would reguire a kill switch as it'd be impossible to switch off the unit in any other way because it would be out of reach. There's one more thing which is not so good: Getting that small control unit with LEDs and MUTE button to the front end of the car would be impossible because of too short wire
What do you think, would the unit work fine and would it really be stealth? Has anyone tried that kind of install before?
Here's an example pic: