When I tour now I tow an Aspen Classic camper trailer. I traded my 2004 Dyna in on a 2009 Street Glide last fall and I'm currently getting my bike setup for towing this summer. The receiver hitch from Hitch Doc is totally invisible when you remove the ball.
What I really want to know is how and where you trailer towing guys attach the wiring socket down by the hitch. Photographs would help too.

 

Don't have a pic, but I zip tied the harness to the hitch sideframe and the last zip tie is on the horizontal piece that the ball goes into. I gave myself enough slack that I can tuck the pigtail up and out of sight when not pulling the trailer.

I think some one makes a bracket, but I also think you can see the connector then, not completely "hidden".

 

and I always carry a few extra zip ties ... just in case!

 

I too have an aspen classic. On my '96 king I have the 6-way wiring connector mounted, with a couple of zip ties, to the left saddle bag rail - between the bag and the fender - you can see it but you have to look.

I also put the brake controller in the left saddle bag.

 

I made a bracket and mounted a four way off of the bolts that hold the bottom of my hitch where it bolts to the saddlebag mounts, don't see it hardly and it's permanent there.

 

i made a detachable pigtail just behind the seat with a deutch connector kit from ebay. when done just unplug and put blank one in to seal it. works nice. Mike