Over the years I have been annoyed by the sun's rays coming in through the side windows because the sun visors in my car were not long enough to cover the space between the door pillar and the edge of the deployed-left (or right) sun visor.
I coined a term to describe what you might be familiar with yourself: "Side-Sunny Days."
I noticed that I was not the only one annoyed by this phenomenon: I have seen other drivers' creative solutions hanging off their sun visors, futilely trying to block out the sun: green pendaflex folders, manila files, newspapers, even boxer-shorts! And hand-held signs, too.
So, I decided to do something about it. I took a piece of corrugated box material, cut it into a rectangle that would wrap around my vehicle's sun visor, with velcro strips holding it in place. Unattractive, but it worked.
After many more design attempts I landed on the tabs-in-slits design, coupled with scoring embedded across the product's body to promote folding -- both of which design elements are viewable on the How-To-Install/Use Page.
Chris, The Inventor
No More Glare For You! // A Unique Solution To A Glaring Problem