This is the location before the mounting plate is installed. There were three factory studs to mount to. I had to add a shim at the back one to raise that point to the level of the plate. I used rubber washers to isolate the plate and a foam pad where the plate contacts the wheel well. The plate is installed under the air intake bracket and uses that bolt also.
This shows the plate in place and mounted. The extra holes in the back are for mounting the battery tray. I used a piece of clear plastic laid over the location to be able to mark where the studs were located and made a template to drill the holes in the plate from that.
This shows the battery tray in place.
This shows the tray in a wider view.
This shows the IBS control panel mounted in the truck cab in the spare change tray location.
Since these pictures were taken, I added a disconnect switch to isolate the second battery from the IBS system for charging from shore power. I have a battery charger wired into the camper that I can charge the battery from when the camper is plugged in to a 120v power source.