I added a LED light bar above the rear window of my 2006 17B because I also carry bikes. I put it above the window so I could run all the wires inside the cabinets and not deal with the wall insulation.
I added a back up light and the capability to turn on the backup light and running lights from inside the trailer so I can use them as exterior lights when camping. Goofy but I like it...
The backup lights are more to show intent than to backup in the dark. They make a pretty good exterior light when things go bump in the night.
The only hard part was running the wires from the upper rear cabinet to the front left lower cabinet, under the front dinette; that is where the main wiring harness junction box is located. Two people can do this fairly easily.
This link discuses the installation.
Rear Full Function LED Light Bar
I think an upper light bar of any orientation is a good thing, even if not carrying bikes. I would have one or two installed if they were an option back then.
Every year the Escapes get better!