Fitting a floor to my Megalite?

I have a MegaLite
One Planet had their tub floor for their version were going cheap last month
So I got one and the price went up
Does anybody here have a One Planet 'Mid who could post pix of how the OP tub floor fixes to the 4Midable?
Or do you just peg out the 4 corners and hope it stays in shape?
I ask because it came with multiple lengths of bungie cord that don't seem to do anything
One Planet had their tub floor for their version were going cheap last month
So I got one and the price went up
Does anybody here have a One Planet 'Mid who could post pix of how the OP tub floor fixes to the 4Midable?
Or do you just peg out the 4 corners and hope it stays in shape?
I ask because it came with multiple lengths of bungie cord that don't seem to do anything