My 1992 348tb has the separate centers on it from the factory. Not sure if they're removable (I never tried) but they're definitely a separate piece.
Here's a pic of my seat bottoms: http://www.researchdevelopmentengineering.com/Gallery_DriverSeat_Logo.htm
mine look like this where the center of the seat bottom isn't separate. Being nearly 30 years old, the leather from the bottom side bolster to the seat bottom itself is giving up. My original question was more about the engineering of them. My design puts the leather in tension as the foam compresses and dies, but the bottoms that the spiders had as well as some later cars put that leather in compression by having the deep groove between the bolster and the bottom. Image Unavailable, Please Login
