I'm happy with mine now. After driving it for a day I decided to add more layers of foam in. I added more of the closed cell foam outboard under the troublesome side bolster, it even makes the turn up to vertical to go partially between the foam and the side of the seat frame. Another layer from side to side under my hips, and then a layer of memory foam over that.
It still looks totally stock as in the photos I posted earlier today (see media recall of seats thread).
Suggest its easier to get foam where you want it if you fully recline the set back. Also suggest multiple layers of closed cell semi rigid foam on the springs for durability, multiple thinner layers for adjustability. See previous posts for info on memory foam too.
Thanks for making the video.
I don't want to officially endorse this mod for the passenger seat as there is an air bag sensor, but I did mod my passenger seat too to match the drivers side, and the sensor in my car still works fine. If you do your passenger seat, it's on you, OK?
My wife feels btw the added "height" now makes the seat back align better as well.
This is a "tunable" mod. I think I'm happy now, but what I did won't necessarily be what you like. The point is it's so easy you can keep tweaking till your happy.
So Mary Barra, if the fix can be this simple, maybe you can get your Dealers to do it...? It's kind of embarrassing that GM didn't figure this out a long time ago.