IDK how this popped up in 'unread' posts, but here it is!
Great idea, great box Geezzer!
My wife and I have made our 'go bags' to fit our trunk and rear of seat, figuring that we will at 'most times' be near out vehicle.
I bought a 'dry bag' from our local military surplus, fits most of the length of the space behind the bench seat. Uses S hooks to suspend vertically.