Hi guys,
This may not be news, but I thought I would post, just in case. Car is a new to me 2008 GS350, which I love. One issue I have had is that when I sit in the drivers seat, the leather makes noise as I shift around. I did find a way to remedy this. It appears what I was hearing was where the leather seat material is meeting the plastic back of the seat. I put on a pair of surgical gloves and cleaned the area where the seats meet the plastic and followed it up with leather conditioner (Tanners).

Problem solved. Now, if I can get the door panels quiet, all will be well.
Hope that helps someone.