Storage/bed solution with rear seats forward?

[orbitelevendk]

We typically travel with the 2nd row seats almost fully forward so we can reach our 2 kids sitting there. This gives us ample room in the rear for luggage, however I can't help but wonder if there was some way to buy/build an expanding/collapsing rear shelf (the one the bed sits on) that would expand to make it so we had two levels of storage when the seats are forward for "driving mode", but could be collapsed when we're in "living/dining mode" with the seats back, and obviously out of the way for "sleeping mode".

Any creative solutions/hacks/bodges out there?