Goldwing Windshield cover, why?

While we were out ridding this weekend I noticed several goldwings
parked with windshield covers. Everything from oem goldwing style to
a t-shirt. What is the purpose for these? I live in Arizona and was
wondering if it is because the sun can cause damage to it?

It's a good idea to cover your windshield in the heat and sun. Lots of guys
use their jackets. The windshield could discolor, but mostly it's because
the heat from the sun will intensify through the windshield. Making the
saddle, tank and handlebars hot enough to fry an egg, or melt a dash.

Thumper

I don't think the sun damages them. But in a dusty place (like
Arizona) dust settles on them, then makes fine scratches when you
clean them. This is more of a problem for bikes where you look
-through- the windshield rather than over it, as you do on the
Goldwing. That big windshield is probably one of the more expensive
to replace.

The sun "reflecting" off the concave side of the shield can create a solar
mirror effect that can melt the dash.

There was a bit on the news about clear water bottles left in cup
holders acting as magnifying glass and burning the cars interior.

I would have thought a dash cover would be more discreet than a
windshield cover.

For the same reason that the chance a bike is ridden in the rain is
inversely proportional to it's price.