I completed the install of our rear bumper shore power receptacle today and wanted to share the details.
This receptacle was used: https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1
It turns out there is an existing route from beneath the rear of the van into the cargo area wall at the rear driver's side corner. I'm guessing it is for the trailer power if you have the tow package. I decided to utilize this, and put the shore power receptacle in the rear bumper.
1) Discover that a ~1/8" steel tube runs behind the rear bumper. Think plan is thwarted. NOTE: If you do not have the parking sensors, it should be easy to mount the receptacle without touching the steel tube. If you do have the parking sensors, you might be able to avoid the steel tube by mounting the receptacle in the corner moulding at the end of the bumper, underneath the light.
2) Buy tungsten carbide grit 1-7/8" hole saw to get through that steel (https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
). Also buy some cutting fluid to keep things lubricated while you are cutting the hole (https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1
3) Cut the hole. Keep it nice and slow with significant pressure on the hole saw. I had to stop and let my cheap drill cool several times. Make sure you keep the saw and steel well lubricated. Once you are through, clean up and primer the hole.
4) Route your triplex AC wire.
5) Connect to the shore power receptacle and push receptacle into the hole, flush with the bumper. I put a 2x4 over the top of the receptacle and gave it a few whacks with a hammer to get it completely flush. Drill pilot holes and use provided screws to secure the receptacle.
6) Steal power from all your friends.