I have the Saturn accessory neoprene covers on my VUE. They are pretty much the same as the Wet Okole covers, perhaps ever so slightly thinner.
They do dampen the heat somewhat - it takes a bit longer to get going. They also slide every imaginable way on leather and overall turn into a complete disaster (I have the sport cloth, so this is a non-issue.) I worked for a dealer for 4 years when I was in college - so I had some experience with them. While driving a then-new 2003 Outdoor Expression edition VUE with leather (yellow exterior, tons of accessories from the factory) back from PDI, I had to stand on the brakes to avoid hitting a car that pulled out in front of me. The cover slid so much that it tore the retaining strap and had to be replaced.