The wood bases are not covered. They are bolted to the floor; then the seat bolts pass thru the bases and are also bolted to the floor. The picture of the base above does not show the countersunk holes for the bolts.

As to the "logic", it's because I can see the bases when I open the door and look down there, especially the cool little "V8" symbols inlaid in the front edge, and I like it Plus, it's "different". Also consider that this wooden base seemed quite a bit simpler to build than most of the nice metal bases like I see some guys building for hot rod seats and most of those metal bases are less visible than mine. Dammit! Next person who gets into my roadster will have to look at these bases whether they like it or not!