I recently replaced the driver's seat bottom and seat back padding on my 91 300TE. I believe my seats are constructed a bit differently than yours (mine are made by Keiper/Recaro) since mine use contoured and formed foam instead of rubberized fiber. The pads from the dealer were about $145 each and really weren't much firmer than the original pads which were identically constructed. I believe most of my improvement came from the re-insertion of the felt pads into the sewn-in pockets in the MB Tex covering. For some reason most of these had migrated out of their respective pockets over the past 230K miles. By doing this I was able to get a bit more lower back support but the entire job is very time consuming. I can almost see why the dealer quoted me $1K to replace the cracked seat bottom frame (known MB defect) on the driver's side of my 01 E320. Mark