Ecru

This may sound like a ridiculous problem but its been bugging me for weeks. Just owned a new LS430. My problem is the driver seat's back rest doesn't provide the necessary upper body support that my specific back needs. I constantly have backaches whenever I drive this car. I think the problem is the foam thats too soft. I opened the seat cover at the back and notice that all springs and wires seems fine. I owned several other luxury cars with numerous seat adjustments so I'm very familiar with each seat functions. Have any of you went to any shop and modified the seats? is it possible to switch the foam from front passenger seat to driver's seat since it provides better support (for some reason)? Does the side airbags integrated on the foam molds?
Any info is appreciated.