I have the factory mattress in my 06 QS10 and wish I had a bit more padding. When I roll over my shoulder and hips feel the foam bottoming out. Due to its age and the fabric showing some wear I want to just replace it. I think my current mattress is about 3 inches thick. Just off the cuff I am thinking about the new one being about 5 inches thick overall. I have interlocking padded foam that is 1 inch thick and brand new. I am thinking about gluing that to the bed and getting a 4 inch mattress on top of it. Id like to hear what types of foam you have used and been pleased with as well as if you went thicker.