Minivan with DIY sleeping platform and drawer system. My weekend of event with rain has just got better! Would have the drawers removable to put strollers under platform and still be able to get out after loading the back from your walmart run.
They added a bar attached to the lantern hanger poles (drilled holes and attaced with a wing nut--could use cotter pins maybe for a quick release system) to hold their pantry. might be a useful option if you didn't add peg board.