Here is a "Blinding Flash of the Obvious."
Next time you are at a car show puchase a large roll of foil backed bubble wrap and line the cab with it using spay adhesive.
When I was at the Spring Charlotte show last year there was a man selling foil backed bubble wrap in bulk. He had it in a 4ft width and varying lengths from 6ft to 100 ft.
I paid $50.00 for enough bubble wrap to line my 41 1 ton pickup,
my 1946 Suburban AND also make window inserts in my Trawler boat to keep the sun out when not cruising.
It gives you an idea what a rip off the windshield inserts are at $25.00 each.
It also reduces the sound levels.
If you live in the Southeast you "must see" this show in April.