I looked around and did not see any posts for this. I have a 2011 Silverado 2500HD. I want to make a box for the back end, accessible from the tailgate. Has any body done or seen this anywhere?

I just want a place to throw in a bag of groceries or dog food or whatever and keep it out of the weather. Chains, jumper cables etc. I will paint it white to match the truck. It is a 4x4 and sits high enough that most people won't see it. Storage in the front of the bed is just difficult at best.

Thanks to all