RARE '58 Pontiac sunvisor (???)

I was just talking with a guy at work who mentioned a rare factory option on 58 Pontiacs. Its a sliding plexigl*** sunvisor--I just tried to do a quick search to see what he was talking about cause it not only peaked my interest but i've never seen one & would like to know more about them so hopefully someone has pics or something? Esp how they work cause it sounds kool and something i would like to try to duplicate.

Any info or pics would be greatly appreciated.
DDR

 

Here you go.

http://www.ev1.pair.com/pontiac_html/58pontiac_2.html

Cool 58 pontiac site in general. Before I bought my starchief I'd visit this site daily .

 

Thats awesome--Thanks for the link!!...Time to do my research and homework!