Here is a homemade sunshade for the nvidia shield.  
If you have access to a plotter, you can plot the pdf file and use for a cutout template.  Some notes on construction:

1.  I used med. weight mounting board availabe at a hobby shop.
2.  I cut on all line effectively creating 6 pieces.  I then used duct tape to connect the pieces back together with about 1/8" spacing between parts so that a hinge would be created that will allow the shade to be folded up.
3.  I covered the outside with white vinyl and inside with black.
4.  Added velcro to the small tabs and upper wings.

It works pretty well for me but would appreciate any feedback from anyone that tries it out.

CP

very nice :-) thanks for the .pdf

That's cool and very useful for many NV Shield users in our forum.Thanks for your sharing.