Taken from the above link (thanks LordHelmet): ... sounds good - but again, I thought most windshield glass already did this.
And then I also thought Solar Control Glass it might just be Kia's way of describing tinted windows. Heck, only the top-level SX is supposed to come with it, so it is plausible. But I wasn't actually at the lot to test the theory.
My suspicions were raised further when my local dealer tried to sell me.. nay force me, to take pre-installed tinting on the car when I bought it. At $499 no less

When I complained about it (hey, I can do it myself for $50 - and get to choose the darkness of the tint) and also mentioned the Solar Control Glass the SX is supposed to come standard with... he mysteriously dropped the charge. Hmmm...