I'll have a car sear in the back of my S (two in a few months...yikes!) and I tend to cinch the seat to the car so it's nice and secure. This puts pressure on the seat and would probably either damage or permanently stretch the leather seats as the base of the car seat presses into the leather. I'm planning on putting something under the base to distribute the load and eliminate potential for any damage. My latest thought is to wrap a square of thin plywood in a towel and place it under the car seat base. Does anyone have any better ideas?