I got a 4"x4"x4" plastic box with a removable gasketed lid at Lowe's. I found a place for it in the front left corner of the front trunk, next to the battery box. I mounted it in place with two bolts and a rubber strip to cushion the box from the vibration.
I then drilled a hole in the lid, sized to the plug from the EA kit.
Here's the plug in place for a test fit.
Here it is in place.
Last step was to land the wires onto the terminal block. The top three terminals run over to the charger.