My 4Runner has a thick strip of heavy tint along the top of the windshield, pictured below. My truck came with it, but it's probably pretty cheap and effective. Unless you just want it for the looks, in which case this doesn't help.
Been searching all over the cant find a manufacturer or any leads to find one, might have to go the custom route. Pops had one on his 2nd gen.
"...but I bet there is a market for them."
People who want to get 4 or 5 mpg less?
Or people that want to make their station wagons look different then the other 100 in the mall parking lot.