Here is the picture of the area before I installed the EMS-HW30C. This is looking through the rear storage compartment door under the bed with the storage compartment wall removed. The pink insulation covers the fresh water storage tank.
I screwed a second small piece of plywood to the left of the transfer switch you see and mounted the EMS-HW30C to the plywood. I then routed the incoming power cable (black cable) through the EMS-HW30C.
Sorry I didn't take another photo after the install.