  We report an investigation of the combined structural and electronic
properties of the bronze Na$_{1.5}$(PO$_{2}$)$_{4}$(WO$_{3}$)$_{20}$. Its low
dimensional structure and possible large reconstruction of the Fermi surface
due to charge density wave instability makes this bulk material a natural
superlattice with a reduced number of carriers and Fermi energy. Signatures of
multilayered 2D electron weak localization are consequently reported, with an
enhanced influence of quantum oscillations. A crossover between these two
antagonistic entities previously observed only in genuine low dimensional
materials and devices, is shown to occur in a bulk crystal due to its hidden 2D
nature.
