Not what you are looking for but somewhat on topic. I installed a Sportster 5 in the RR over the weekend. I used one of those adjustable vent clip devices to hold the dock and radio, then spiced in another 12v cig outlet behind the HVAC panel by removing the right side kickplate. I just tapped into the existing cig outlet 12v since I don't use that one - prefer to keep the ashtray door shut, I don't like things laying around the shifter or hvac controls.
Ran the 12v inside the kickpanel edge where it meets the padded dash. Tucked in nicely. Ran the antenna from the radio (the vent clip and radio are on the center stack, right side vent) along the same seam, then below the glovebox along the edge of the plastic tray that holds the extra antenna wiring nicely. Two sided tape and stuck the antenna on the front of the dash right next to the A pillar where it gets a clear shot at the sky (use the same method in all my cars and rarely get a signal loss - no need to run it outside the vehicle).
Since I have 4 cars with dock and 2 Sirius recievers, 2 home docks, and an boombox dock in my office, this way made the most sense for me.
The end result is a dock in a nice, visible position that doesn't interfere with your sightlines, and since it is a single occupancy vehicle 99% of the time the passenger won't miss that vent adjustment.
Took me about a half an hour.