A little bit of both. They are shaped to fit within the contours of the molded floor carpet for that "floating" appearance, but they are also freestanding through some strategically placed "feet" that support the components on a solid base. Both platforms are bolted to the cabin floor with some hidden brackets.Hi Raine, i like the build, keira is beautiful. Question, so im looking through your build thread and not seeing detail on how you mounted the amp wood platforms to the cab floor to keep them level? Or are they floating on the higher edges of the flooring or secured and leveled in some other way? Thanks again for all the great info.