The present invention relates to a wireless car digital AV system to be applied in a car, and the wireless car digital AV system comprises an AV Host and at least one or multiple display devices. A support body having a plurality of recesses formed on an internal wall of the modular printer is also provided. Investment costs significantly decrease due to the decrease in the number of columns, decanters, and auxiliary equipment, spare parts, materials inventories and the requisite area for the plant relative to a standard prior art plant.