Strength of plastic floor in trunk of 2004 Prius?

How strong is that plastic that covers the wheel and jack in the trunk of the 2004 Prius? (It's the carpet covered plastic that forms the visible floor of the trunk in the Prius.)

We had to move about 600 lbs of packaged flooring and I was a bit worried about that plastic cracking, since much of the weight would have been centered on that plastic sheet. Thus, just to be safe we moved 300 lbs at a time.

 

Thanks, but all I can come up with is a 840 lb total load (incl. passengers). That would not be a major problem, given the the cargo I was carrying was less than 600 lbs.

What I'm wondering is how strong the carpeted plastic cover of the bottom of the trunk is.