That doesnt look like a cover to me it looks like a rollpan.
Checkout
http://www.sirmichaels.com/ they have them for Tundras. It replaces your entire rear bumper with a steel rolled type bumper. It will have to be painted to match your factory color. I had one on my tacoma for a little while and they look nice but you lose having an actual bumper so keep that in mind.