The filler is a opening like a washer bottle out the top of the bottle, which you can poke out through your side panel, and the access to the water is via a hose which sticks out through the bottom of the panel, with a tap on the end.
This pic below gives you an idea, and you can make a new...
Hey AZ_Man, I hope your name means your from Arizona, and not that your a pillow biting shirt lifter :flipoff2: :D
I deal with these tank people with my shop www.offroadshop.com.au and if I get a template sent to me, or a drawing, we could perhaps get some added to our next US shipment?
I...
They will make any size to fit amywhere, the straight ones which lay on the back floor can be stood on, if you ahve kids in the back, and are quite strong.