Ken,
I just did this this summer. After lots of research I found that there's a trailer connection in the storage tray just inside the tailgate. I installed diodes to isolate the Pilot wiring from wiring running from motor home. I did run wires under the Pilot to a grommet in the bottom of the storage tray. They could be run through the firewall and back under the carpet. After the 100 degree day I picked to do this I should have gone the carpet route, but...
For more information on where to find the trailer wiring do a search on Piloteers.com. It's an excellent forum for help with all the oddities of the Pilot. Some on there will try to tell you the Pilot can't be flat towed. Ignore them!!
Hope this helps you. It is not a simple installation.