Here is the finished product:
And what's under the carpet:
There are two storage areas - one in the tire hub and the other on the left, under the hinge:
The post keep the hinged area flat and allows material to be stored on it. I hold the tire down with a bolt and hold the platform down with a tie-rod:
Right now I have jumper cables in the tire hub and the 120v EV cable, air pump and umbrella in a bag under the hinged area.
I used the floor mat as a template for the 1/2" plywood platform. All told took about 1/2 day and I feel a lot better with the spare.
Thanks for the image help - flickr did not work but postimg.org works fine.