I work in San Francisco, so I own a van to keep my tools secure.
I built a hollow deck about 4" thick, 12" off the van deck, that is the width of the sliding door. The deck is divided into slots for the guide rails, 4' levels and miter saw wings. Everything just slides in. I store my Festools and miter saw on top.
I used some cheap "agathis " ply from Home Cheapo, that was a mistake, if I did it again, I'd use some 1/2" struc1 or MDO (although I hate the smell of that stuff) and poplar cross pieces for the deck
I do take the MFT to job sites, it's not light but it weighs only 55lbs, no the 75lbs listed in the catalog. I use it as a miter stand & work table, an outfeed table and door bench. it takes a little modification, but it works well.
I fixed the height issue by moving the long legs to the lower holes and adding a piece of PVC pipe top the short feet (I think I used a PVC P-trap, slip joint extension)