Glen,
You're right... there is a seal to stop dust/water from entering the boot area...
But I think the following will answer Box's question.
I think this is a pretty cool feature as well.
The finished boot area will have a panel that sits flat against the floor, but when you have a boot full of gear...this panel covers the suspension.
It swings up and is held in place with magnets.
Here's a quote from the Owner's manual:
The centre piece is designed to pivot at the front edge upwards and magnetically fasten to the zinc plated steel brackets fastened to the boot hinge mounting for the curved round tube.
The magnets are fastened into the centre panel.
and a couple of pics to show what we mean.
Cheers ( Happy New Year )
Wazza