You might want to see if the FrontRunner Wolfpack boxes will support your additional piece that folds down where your piano hinge is. They are 9" tall and fit perfectly in the backs of the rear seats. Great place to store your least used items such as tools and recovery gear.
Anyway, just throwing out an idea.
As you can see, there is plenty of room to slide them in and out of the passenger door opening.
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This is what the look like side-by-side resting on the backs of the rear seats. Again, plenty of room and they're not permanent. When you're done, just remove them and put them on your shelf in the garage. Ready for your next trip.
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Her's an example of what I keep in one of the boxes. I have an ARB tire repair kit, a couple of gator jaw soft shackles, a snatch block, an ISC (RP057) rigging pulley, tree saver, tool rolls along with a few other miscellaneous items. This box is a necessity but not used if all goes well.
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