I was agonizing about a decent separation screen for the 4R. My dog is a nut in the car, and his mission is to try to get up front. And he is a window licker. I personally hated all the options available, so I ended up just buying the proper sized, double door crate for my dog from ebay and securing it to the D-rings with straps. For my particular breed, it fits perfectly. It has two benefits- my dog is a lot safer in that he can't run back and forth and God forbid we get into an accident he will not be tossed around as far. Secondly, I can also put stuff in the back besides the dog.
I have, however, been thinking about a barrier net nonetheless- I was transporting a dresser with the drawers in, and at one point I stopped short and the top drawer slid out and almost knocked me unconscious. I'm thinking about a 1/2" tubular webbing net, form fitted, and attaching using existing points. My friend has an industrial sewing machine, and makes holsters and packs and such, so it would be no problem for him.
