I didn't realize you responded. Neoprene, as used in wet suits, is a closed cell product. Imagine a sponge that does not absorb water. That is why they use it in wet suits, it doesn't allow the water to escape, except at the neck, arms, legs, and seams. This allows your body to warm the water up that is caught under the wet suit and adds a thin layer of insulation. It probably can't be listed as waterproof because typically the seams allow water to pass, unless they are also sealed, although it all depends on how the covers are made.

I could see where getting water under the cover could cause problems for a seat. If water were to ever get under there, it wouldn't be able to evaporate quickly. If you used them over a leather seat it suddenly puts moisture back into dead leather, which I would think, would lead to rotting and other moisture problems.

 

Going to the lake in the 2010 King Ranch and i took some plush beach towels and put gromets in them so that i could put the headrest post through them and then an closed latch "S" hook on the metal brackets for the child saftey seats. It holds the towels in place and can be installed/removed in 2 minutes. I will store them under the rear seat and pull out and attach on the way to the lake.

I also did one for the rear of the front seat that i will use anytime i transport the little guy. He was always putting his feet on the rear of the front seat to push himself back into his car seat. This way i keep his foot prints off of it and it installs quickly. So now the rear seat and the rear of the front will be protected when putting in the car seat. Cost was about $15 (towels, "S" hooks, hammer in grommets) and 1 hour time total.

 

finally got the seat cover from sportsmanguide.com that i ordered. it is not the dimensions that they told me over the phone and is actually smaller than they said. not worth returning as the postage would be half the value of it. i will keep it and have them sit on it coming back from the beach. will not install as i had planned to do. have it folded and stored in a front seat back pouch.