Keeping the sun out of your eyes at car shows...

Most times at car shows you need to create your own shade.  This is typically done with a pop-up canopy, assuming that the show will allow it and assuming you have room in your car.

Here are a couple of other options:

link to chair 1 

Chair link 2

Chair 3 link

http://www.renetto.com/Original_Canopy_Chair_s/6.htm

They have something like this at CostCo:

http://sport-brella.com/