Borrowed this idea from Brian Lopes MTB Sprinter build to use in my Express AWD. Basically just mounted the tray's on two sections of airline track bolted to a 3/4" piece of plywood. Found a place that sells these brackets that mount to E-track and provide 2 threaded bolt holes so I used those and bolted the whole thing to the E-track on the floor of my van with easily removable hand knob bolts. Also used hand knobs to attack the trays to the airline track so they are easily removable/adjustable as well.