Engel Transit Lock???? Fridge Placement

[BarneyRubble]

Hi Peeps,
I need to know the thickness of the transit locks for the Engel's. I want to put one under my back seat, but still be able to lower the seat for people when the fridge isnt in.

If anyone has one could they do me a favor and measure the thickness of them? I know I have about an inch to play with...

If anyone has other options to mount the fridge this would be great... PS. I don't have a canopy with drawers and don't want to get one yet...