I forgot my Snap on jumper(probably the same as yours) in a customers car when I was at the dealership, Freaked out as they wouldn't answer the phone.
A week later they called...they went right to the airport when they picked the car up...it was still in the back on the floor..WHEW!!! I got lucky..
I know not a dune story but made me remember about the jump box.
I know I have lost plenty out at the dunes just cant think of anything right now.